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Key to Carex

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Show caption*© Scott Ward
1 Spike 1 per culm, all flowers attached to the main stem in a terminal spike
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Show caption*© Gary P. Fleming
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Show caption*© Keith Bradley
1 Spikes 2 or more per culm (some flowers in lateral spikes)
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  2 All flowers staminate
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  2 At least some flowers pistillate.
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    3 Stigmas 2; achenes flat or biconvex in cross-section (lenticular)
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    3 Stigmas (2-) 3 (-4); achenes trigonous or terete in cross-section.
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      4 Body of perigynium pubescent, scabrous, hispid, or papillose (if papillose, the papillae longer than wide)
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      4 Body of perigynium glabrous or papillose (if papillose, the papillae shorter than wide).
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        5 Bracts sheathless or with sheath < 4 mm long (rarely longer, and then the sheath shorter than the diameter of the stem)
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        5 Bracts (at least the lower) with sheath > 4 mm long (and longer than the diameter of the stem)

Key to Carex, [26a] Section 1a Vulpinae: section Vulpinae

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1 Leaf sheath fronts yellow, thickened, and not fragile at the top; leaf blades papillose adaxially (at 25× magnification)
1 Leaf sheath fronts green or whitish, thin, and fragile at the top; leaf blades not papillose adaxially.
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  2 Leaf sheath fronts smooth.
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    3 Larger perigynia 6-8 mm long; leaves to 12 mm wide
    3 Larger perigynia 3-5 mm long; leaves to 7 mm wide.
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      4 Perigynia smoothly rounded at base, not distended; perigynium veins 3-5 abaxially, 0 adaxially
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      4 Perigynia cordate at base, distended; perigynium veins 10-12 abaxially, 7 adaxially
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  2 Leaf sheath fronts rugose.
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        5 Perigynia broadly rounded at base, not distended; perigynium veins 3-5 abaxially, 0 adaxially
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        5 Perigynia cordate or truncate at base, distended; perigynium veins 15 abaxially, 7 adaxially.
          6 Perigynia (5-) avg. 5.4 (-6) mm long, the beak > 3 mm long; larger leaves mostly 8-17 mm wide; perigynium scales cuspidate to short-awned; [mostly of the Coastal Plain and lower Piedmont]
          6 Perigynia (4-) avg. 4.7 (-5) mm long, the beak < 2.5 mm long; larger leaves mostly 4-10 mm wide; perigynium scales acuminate to cuspidate; [widespread in our area]

Key to Carex, [26a] Section 1b Vulpinae: section Vulpinae

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1 Beak of the perigynium shorter than the body.
  2 Perigynia somewhat abruptly contracted into a beak ca. 0.5 × as long as the perigynium body; ventral surface of the perigynium with several incomplete veins basally; culms sharply triangular and narrowly winged, somewhat spongy and easily crushed; dorsal leaf sheaths green; ventral leaf sheaths with scattered red dots, and transversely rugose; [normally of shaded locations]
  2 Perigynia tapering into a beak, much shorter than the perigynium body; ventral surface of the perigynium with several inconspicuous complete veins; culms inconspicuously triangular to roundish, not winged, neither spongy nor easily crushed; dorsal leaf sheaths dark blue-green with conspicuous white dots; ventral leaf sheaths without scattered red dots, not transversely rugose; [normally of sunny locations]
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1 Beak of the perigynium as long as, or longer than, the body.
    3 Ventral leaf sheath margins with orange-red dots; achene ovate-lanceolate; perigynium wall adhering to achene
    3 Ventral leaf sheath margins without orange-red dots; achene broadly ovate to ovate-orbicular; perigynium wall not adhering to the achene (or only slightly so).
      4 Ventral leaf sheaths not transversely rugose, more or less concave at the apex and not prolonged upward past the base of the blade, thickened, not friable
      4 Ventral leaf sheaths transversely rugose, more or less convex at the apex and prolonged upward past the base of the blade, friable.
        5 Perigynia (5-) avg. 5.4 (-6) mm long, the beak > 3 mm long; larger leaves mostly 8-17 mm wide; perigynium scales cuspidate to short-awned; [mostly of the Coastal Plain and lower Piedmont]
        5 Perigynia (4-) avg. 4.7 (-5) mm long, the beak < 2.5 mm long; larger leaves mostly 4-10 mm wide; perigynium scales acuminate to cuspidate; [widespread in our area]

Key to Carex, [26aa] Section 18 Paniceae: section Paniceae

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1 Perigynia with a distinct beak, 1.0-2.2 mm long.
  2 Basal leaves with well-developed blades; basal sheaths brown; perigynia glabrous; [of moist, usually calcareous habitats of the Coastal Plain]
  2 Basal leaves reduced to bladeless sheaths; basal sheaths strongly purple; [of dry, acidic habitats of the Mountains]
1 Perigynia beakless, or with an indistinct beak < 0.5 mm long.
    3 Perigynia strongly ascending; leaves coriaceous, involute, glaucous; [s. NJ northwards]
    3 Perigynia ascending or spreading; leaves herbaceous, flat or folded, green or slightly glaucous; [collectively widespread].
      4 Basal sheaths with well-developed blades; basal sheaths brown to strongly purple.
        5 Pistillate spike 5-7 mm in diameter, with ca. 6 vertical rows of perigynia; perigynia 3.3-4.2 mm long, 2.0-2.5 mm wide; leaves 3-7 mm wide, blue green
        5 Pistillate spike 3-4 mm in diameter, with ca. 2-3 vertical rows of perigynia; perigynia 2.5-3.5 mm long, 1.5-2.0 mm wide; leaves 2-4.5 mm wide, pale green
      4 Basal sheaths bladeless, or with blades to 3 cm long; basal sheaths strongly purple.
          6 Culms to 10 dm tall, (2-) 3-5 mm in diameter near base; larger leaves ca. 5 mm wide; plants forming large clumps; [plants of shallow soils on sloping rock outcrops]
          6 Culms to 5 dm tall, ca. 1-2 mm in diameter near the base; larger leaves ca. 2-4 mm wide; plants forming small, spaced clumps, interconnected by long-creeping rhizomes; [plants of mountain slopes in more-or-less deep soils]

Key to Carex, [26aaa] Section 38 Leucoglochin: section Leucoglochin

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1 One species
1 One species

Key to Carex, [26b] Section 2 Heleoglochin: section Heleoglochin (Paniculatae)

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1 Inflorescence 7-15 cm long, the basal 3-9 branches well-separated from one another; perigynia broadly obovoid, 1.3-1.5× as long as wide; sheaths concave at the mouth; leaves 3-8 mm wide; [of swamps of the Coastal Plain and lower Piedmont]
1 Inflorescence 2-8 cm long, the basal 1-5 branches indistinct to slightly separated; perigynia ovoid to lance-ovoid, ca. 2× as long as wide; sheaths prolonged beyond the blade; leaves 1-3 mm wide; [of Mountain wetlands in VA (and TN?) and northward].
  2 Inner band of leaf sheath whitish (and red-dotted); basal branches of inflorescence overlapping; perigynia not concealed by the scales
  2 Inner band of leaf sheath strongly copper-colored (and also red-dotted); basal branches of inflorescence often weakly separated; perigynia nearly or completely concealed by the scales

Key to Carex, [26bb] Section 19 Laxiflorae: section Laxiflorae

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1 Perigynia with 8-18 veins, 2-3 conspicuous, narrowly cuneate basally; perigynium beak short and usually abruptly bent; foliage dark green; bracts surpassing the staminate spike
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1 Perigynium with (22-) 25-32 veins, all of which are conspicuous (the central one slightly more distinct); perigynium beak various; foliage various; bracts various.
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Show caption*© Quinten Wiegersma, some rights reserved (CC BY), uploaded by Quinten Wiegersma
  2 Perigynium with a short, bent beak, usually abruptly bent to one side.
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    3 Spikes loosely flowered, most perigynia not overlapping.
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      4 Bracts very broad, 8-20 mm wide; basal leaves very wide, up to 40 mm wide; plant glaucescent; basal sheaths purple or brown
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      4 Bracts narrow, 2.5-6 mm wide; basal leaves narrow, 3-8 mm wide; plant green; basal sheaths purple, often weathering to brown
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    3 Spikes densely flowered, the perigynia overlapping.
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        5 Basal sheaths purple when fresh, weathering to brown; uppermost bract rarely overtopping the staminate spike; staminate spike usually long-stalked
        5 Basal sheaths brown; uppermost bract overtopping the staminate spike; staminate spike sessile or short-stalked
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          6 Widest bract of the uppermost lateral spike 0.5-3.4 mm wide
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          6 Widest bract of the uppermost lateral spike (2.9-) 3.2-8.3 mm wide
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  2 Perigynium tapering to a straight or slightly curved beak (or a long, curved beak in C. radfordii) (note: some beaks may curve in pressing).
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             7 Perigynium beaks long (to 1.5 mm long) and excurved; basal sheaths green, white, and brownish striped; [endemic to the escarpment gorge area near the SC-NC-GA tricorner]
             7 Perigynium beaks straight or slightly curved; basal sheaths either purple, wine-red, or brownish, not prominently green-and-white striped; [collectively widespread in our area].
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               8 Basal sheaths purple or wine-red (may weather to brown in C. gracilescens).
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                 9 Spikes densely flowered, the perigynia overlapping
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                 9 Spikes loosely flowered, the spikelets not overlapping.
                   10 Mature leaf blades of sterile shoots 4-5 (-6) mm wide, green; culms green, chalky red at base (best seen in fresh material); pistillate spikes (3-) 5-7 (-8) flowered; staminate spike on a peduncle 0-1 cm long
                   10 Mature leaf blades of sterile shoots (6-) 7-10 mm wide, glaucous; culms glaucous, bright red at base (best seen in fresh material); pistillate spikes (4-) 7-11 (-15) flowered; staminate spike on a peduncle 2-3 (-6) cm long
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               8 Basal sheaths brown, not purple or wine-red.
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Show caption*© Paul Marcum, some rights reserved (CC BY-NC), uploaded by Paul Marcum
                     11 Mature perigynia obovoid.
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Show caption*© Jake Smith, some rights reserved (CC BY-NC), uploaded by Jake Smith
                       12 Spikes overlapping, densely flowered; staminate spike more-or-less obscured; plant green
                       12 Spikes scattered, loosely flowered; staminate spike prominently exserted; plant usually glaucescent
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                     11 Mature perigynia fusiform.
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                          13 Spikes overlapping, the staminate more-or-less obscured and overtopped by the uppermost bract
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                          13 Spikes scattered, the staminate prominent and exceeding the uppermost bract.
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                            14 Spikes densely flowered; perigynium beaks curved; lowest spike exserted on a long, arching, peduncle
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                            14 Spikes loosely flowered; perigynium beaks straight; lowest spike on a short, erect or ascending, peduncle
                              15 Widest leaf on vegetative shoots (including overwintered leaves) 2.0-6.0 (-6.9) mm wide; medial pistillate spikes more loosely flowered, the ratio of the number of perigynia to spike length (measured in mm) (0.20-) mean 0.41 (-0.52)
                              15 Widest leaf on vegetative shoots (including overwintered leaves) 5.7-11.3 mm; medial pistillate spikes more densely flowered, the ratio of the number of perigynia to spike length (measured in mm) (0.47-) mean 0.57 (-0.90)

Key to Carex, [26bbb] Section 39 Acrocystis: section Acrocystis (Montanae)

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1 Primary culm accompanied by pistillate spikes borne on short or elongate peduncles from the same sheathed base (referred to as subradical or basal spikes).
  2 Terminal staminate spikes alone or associated with a pistillate spike; lower pistillate scales acuminate, mostly exceeding the perigynium beak; perigynia lacking discernible papillae.
    3 Perigynia (2.2-) 2.3-3.2 (-3.3) mm long; perigynium beaks (0.4-) 0.5-0.9 mm long; young leaves long, thin and flexuous
    3 Perigynia (3.0-) 3.1-4.7 mm long; perigynium beaks (0.9-) 1.0-2.1 mm long; young leaves variable.
      4 Perigynium body usually pubescent; young leaves long, thin and flexuous
      4 Perigynium body essentially glabrous, with a few hairs on the angles of the beak only; young leaves short, broad and rigid
  2 Terminal staminate spikes usually with at least one approximate pistillate spike; lower pistillate scales acute, mostly shorter than the perigynium beak; perigynia distinctly papillate, at least at the base of the beak (except C. deflexa).
        5 Staminate spikes 3.2-5.6 mm long; perigynia with broadly deltoid beaks, coarse spreading trichomes, and indiscernible papillae; basal spikes 0-1 (-2)
        5 Staminate spikes 3.6-16.8 mm long; perigynia with narrow beaks, finer spreading trichomes, and papillae evident; basal spikes 1-2 (-3).
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          6 Perigynium body elliptic, with adaxial and abaxial surfaces lacking hairs (some often present on angles of the beak only), papillae prominent; [se. Coastal Plain]
          6 Perigynium body round-elliptic, with adaxial and abaxial surfaces pubescent, papillae concentrated mostly below the beak; [ne. North America and southern Appalachians].
             7 Staminate spikes large, 6.8-16.8 × 1.0-2.9 mm, exceeding adjacent pistillate spikes by 4.7-16.5 mm, peduncles 3.5-13.5 mm long; culm bracts setaceous, 0.1-0.3 mm wide, and mostly shorter than the inflorescence.
               8 Culms much shorter than longest seasonal (green) leaf; primary culms with 0-1 (very rarely 2) pistillate spikes; staminate spikes 6.8-11.0 × 1.0-1.7 mm; adaxial perigynium body with spreading hairs; [ultramafic fens of nw. NC & sw. VA]
               8 Culms subequal to exceeding longest seasonal (green) leaf; primary culms with 1-2 pistillate spikes; staminate spikes 8.0-16.8 × 1.0-2.9 mm; adaxial perigynium body with fine sub-appressed hairs; [granitic seepages; escarpment of nw. NC mountains]
             7 Staminate spikes smaller, 3.6-9.0 × 0.7-1.5 mm, exceeding adjacent pistillate spikes by 1.3-8.9 mm, peduncles 0.9-3.9 mm long; culm bracts broad or setaceous, 0.3-0.8 mm wide, shorter than to exceeding the inflorescence.
                 9 Primary culms to 20.2 cm tall; longest staminate spikes 4.1--9.0 mm long; [s. Appalachian]
                 9 Primary culms to 13.5 cm tall; longest staminate spikes 3.6--6.2 mm long; [disjunct south to WV]
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1 Primary culm solitary (i.e., lacking additional basal spikes originating from the same sheaths, excepting hybrids); however, some taxa may exhibit deceptively short individual culms (e.g., C. emmonsii, C. nigromarginata, C. reznicekii).
                   10 Body of the perigynium subglobose to obovoid, usually about as wide as long; achene angles broadly rounded.
                     11 Plants cespitose; leaves 0.9-4.7 mm wide; perigynium body pubescent, often with weak veins on the adaxial surface.
                       12 Lowest proximal pistillate bract often shorter than the large, 3.5-15.5 mm long, terminal staminate spike; widest leaves usually > 3.0 mm wide; perigynia beaks narrow, surfaces papillate, often with weak veins on the adaxial surface
                       12 Lowest proximal pistillate bract often exceeding the small, 3.2-5.6 mm long, terminal staminate spike; widest leaves typically < 3.0 mm wide; perigynia beaks deltoid, surfaces lacking easily discernible papillae and veins
                     11 Plants with long rhizomes, forming clonal patches; leaves 1.0-3.0 (-3.5) mm wide; perigynium body pubescent to nearly glabrous.
                          13 Larger perigynia 1.7-2.2 mm wide, papillae indiscernible under dense whitish trichomes; upper staminate scales acuminate to long-acuminate
                          13 Larger perigynia 1.2-1.7 mm wide; upper staminate scales acute to acuminate, papillae evident or not.
                            14 Beak of perigynium (0.8-) 1.3-2.0 (-2.4) mm long; perigynium body pubescent or nearly glabrous, with or without papillae.
                              15 Beak of the perigynium 1.1-2.4 mm long; widest leaf 1.3-2.3 (-3.7) mm wide; perigynium glabrous to sparsely pubescent over the body, papillae usually absent; culm nearly smooth; [of VA, WV, and KY southward]
                              15 Beak of the perigynium 0.8-1.9 mm long; widest leaf 1.9-4.4 mm wide; perigynium usually moderately to densely pubescent over the body (rarely glabrate), papillae usually present; culm often scabrous; [of MD, NJ, and PA northward]
                            14 Beak of perigynium (0.2-) 0.5-0.9 (-1.3) mm long; perigynium body pubescent and papillate.
                                16 Beak of perigynium (0.5-) 0.6-1.3 mm long; hairs at base of the beak and below densely short-retrorse only on both surfaces; [high elevations of the s. Appalachians]
                                16 Beak of perigynium (0.3-) 0.5-0.9 mm long; hairs at the base of the beak antrorse and those below either spreading, antrorse, or with retrorse hairs largely confined to one surface; [collectively more widespread].
                                  17 Widest leaves to 2.9 mm or greater; proximal bracts leaf-like; perigynia 2.3-3.7 mm long x 1.1-1.7 mm wide
                                  17 Widest leaves to 2.2 mm; proximal bracts setaceous; perigynia 2.2-3.2 mm long x 0.8-1.4 mm wide
                   10 Body of the perigynium ellipsoid, distinctly longer than wide; achene angles narrow to slightly rounded.
                                    18 Plants with conspicuously long rhizomes, forming clonal patches; perigynia typically papillate; [collectively of the Coastal Plain and, less commonly, Piedmont].
                                       19 Achene body (1.1-) 1.2-1.3 (-1.4) mm long, trigonous; fertile culms 20-43 cm tall, equaling or exceeding the leaves; basal sheaths usually not fibrillose; pistillate scales (2.3-) 2.6-3.0 (-3.4) mm long
                                       19 Achene body (1.4-) 1.5-1.7 (-2.0) mm long, biconvex, trigonous, or both; fertile culms 7-17 cm tall, usually much shorter than the leaves; basal sheaths usually very fibrillose; pistillate scales (2.7-) 3.0-3.7 (-4.2) mm long
                                    18 Plants cespitose (sometimes loosely so from slender rhizomes in C. novae-angliae and C. peckii); perigynia papillae not evident to rather conspicuous; [collectively widespread in our area].
                                         20 Pistillate scales usually shorter than the body of the mature perigynia they subtend, perigynia without easily discernible papillae, lowermost 2 pistillate spikes remote, several separated by > 7 mm, staminate spike often elevated above pistillate spikes; leaves thin, delicate 0.7-1.5 mm wide
                                         20 Pistillate scales mostly longer than the body of the mature perigynia they subtend, perigynia with discernible papillae, lowermost 2 pistillate spikes overlapping, usually separated by < 7 mm, staminate spike often closely associated with pistillate spikes; leaves various.
                                           21 Plants slender-rhizomatous; pistillate scales longer than the mature perigynium body; perigynia surfaces villous, papillae obscured
                                           21 Plants cespitose; pistillate scales shorter than the mature perigynium body; perigynia surfaces short pubescent to glabrate, papillae conspicuous.
                                             22 Achene body (1.3-) 1.4-1.6 (-1.7) mm long; fertile culms mostly 2-20 cm tall; pistillate scales 2.6-4.3 mm long.
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                                               23 Culms usually variable in length, (4.5-) 6.6-38 (-51) cm tall; widest leaf (1.9-) 2.3-4.5 mm wide; at least some pistillate scales often with reddish to purplish/black color below the distal tip extending laterally from near the margin to the green or brown longitudinal mid-stripe on either side of midvein
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                                               23 Culms subequal in length, height 1.9-9.9 (-13.7) cm tall, widest leaf 1.2-2.2 (-2.5) mm wide; any reddish color on pistillate scales below the distal tip not extending laterally from near the margin to the green or brown longitudinal mid-stripe on either side of midvein
                                             22 Achene body (0.9-) 1.2-1.3 (-1.5) mm long; fertile culms mostly 17-35 cm tall; pistillate scales 2.0-3.4 mm long.
                                                 24 Scales of the median portion of the staminate spike with obtuse apices and with minute teeth rarely present on the midrib; staminate spike (7.8-) 8.0-12.5 (-13.5) mm long with peduncles mostly 1.0-6.0 mm; culms erect, subequal to the leaves; [mostly of loamy or clayey soils of the Piedmont and Mountains]
                                                 24 Scales of the median portion of the staminate spike with acute-acuminate to aristate apices and with minute teeth usually present on the midrib; staminate spike (1.6-) 3.6-8.5 (-9.1) mm long with peduncles mostly 0.3-1.9 mm, exceeding uppermost pistillate spikes by 1.1-5.9 mm; culms lax to erect, often shorter than and curving under the leaves; [mostly of acid, sandy soils of the Coastal Plain]

Key to Carex, [26c] Section 3 Multiflorae: section Multiflorae

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1 Perigynia red-dotted
1 Perigynia not red-dotted.
  2 Perigynia golden yellow or yellowish-brown at maturity
  2 Perigynia dull yellow-green or pale brown at maturity.
    3 Leaves longer than the flowering stem; perigynia 2.0-3.2 mm long, 1.3-1.8 mm wide, the beak 1/3-1/2 the length of the body
    3 Leaves shorter than the flowering stem; perigynia 3.2-4.0 mm long, 2.0-2.6 mm wide, the beak ca. 1/3 as long as the body.
      4 Awn of pistillate scales 1-3 mm long; adaxial surface of perigynia with 3-5 nerves; [wet pine savannas; se. S, south to c. peninsular FL, west to LA]
      4 Awn of pistillate scales 0.5-1.5 mm long; adaxial surface of perigynia lacking nerves; [prairies; s. IL, MO, se. KS, and OK south to AR and se. TX, and also introduced eastwards in disturbed sites]

Key to Carex, [26cc] Section 20 Granulares: section Granulares

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1 Plants with long-creeping rhizomes, the culms therefore mostly solitary; terminal spike and uppermost lateral spike usually separated.
  2 Staminate scales with apex rounded to obtuse; widest leaves 1.8-3.0 (-4.4) mm wide; perigynium beak 0.1-0.3 mm long; [widespread]
  2 Staminate scales with apex acute to awned; widest leaves 2.8-8.3 mm wide; perigynium beak 0.3-0.9 mm long; [Panhandle FL and AL westward]
1 Plants with short rhizomes, the culms therefore clumped; terminal and uppermost lateral spike usually overlapping.
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    3 Leaves green; longest bract blade of uppermost lateral spike 1.6-4.6 (-7.1) cm long; perigynia (1.6-) 1.9-3× as long as thick; [Coastal Plain; NC s. to FL, w. to MS]
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    3 Leaves glaucous (rarely green); longest bract blade of uppermost lateral spike 4.1-15.8 cm long; perigynia 1.4-2.2 (-2.4)× as long as thick; [widespread]

Key to Carex, [26ccc] Section 40 Clandestinae: section Clandestinae (Digitatae)

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1 Pistillate scales short-awned
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1 Pistillate scales acute

Key to Carex, [26d] Section 4.0 Phaestoglochin: section Phaestoglochin (Bracteosae)

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1 Sheaths loose, membranaceous, and fragile on the ventral side, septate-nodulose and usually mottled or striped with green and white on the dorsal side; widest leaves 3-10 mm.
  2 Bodies of pistillate scales 1.5-2.5 mm long, 1.1-1.8 mm wide, mostly < ½ as long as the perigynia, apex obtuse to acuminate to shortly awned.
    3 Basal internodes of the inflorescence usually < 1 cm long, and usually < 2× as long as the spikes; bodies of perigynia with wing < 0.1 mm wide
    3 Basal internodes of the inflorescence usually >2 cm long, at least 2× as long as the spikes; bodies of perigynia with wing 0.1-0.2 mm wide
  2 Bodies of pistillate scales 2.2-4.4 mm long, 1.2-2.4 mm wide, mostly > ½ as long as the perigynia, apex acuminate to awned.
      4 Fronts of leaf sheaths yellow or brownish, thick, firm, the back often white-spotted
      4 Fronts of leaf sheaths white, hyaline, fragile, the backs not white-spotted.
1 Sheaths tight on the ventral side, neither septate-nodulose nor mottled with green and white on the dorsal side.
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        5 Perigynia not conspicuously corky-thickened at base.
          6 Inflorescence ovoid in outline, the spikes densely aggregated, nearly indistinguishable except by the projecting setaceous bracts which subtend each spike.
             7 Perigynia 1.3-1.7× as long as wide, widest near the broadly rounded, truncate, or even subcordate base
             7 Perigynia 1.6-2.5× as long as wide, widest just below the middle, the base broadly cuneate to rounded.
               8 Pistillate scales (excluding the awns) shorter than the perigynium body; culms not greatly exceeding the leaves
               8 Pistillate scales (excluding the awns) as long as or exceeding the perigynium body; culms much exceeding the leaves
          6 Inflorescence spicate-racemose, the individual spikes readily distinguishable (often separated by an exposed internode of the axis).
                 9 Pistillate scales brown or reddish-purple; [exotic, sparsely naturalized in our area].
                 9 Pistillate scales green, hyaline, or pale tan; [native in our area (except C. austrina and C. muricata ssp. lamprocarpa), common and widespread in our area].
                   10 Spikes with 5-10 perigynia; pistillate scales brown with green-veined center
                   10 Spikes with 8-20 perigynia; pistillate scales scarious-white (rarely brown) with green-veined center.
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                     11 Perigynia ascending, nerveless on the ventral surface; scales awned, the awns 1.5-4 mm long; lowest inflorescence bract elongate, the free portion 1-5 cm long
                     11 Perigynia spreading, either nerved or nerveless on the upper (ventral) surface; scales acuminate or with an awn to 1.5 (-2.0) mm long; lowest inflorescence bract short, delicate, the free portion 0.5-2 cm long.
                       12 Perigynia 3.0-3.5 mm long, nerveless on the upper (ventral) face
                       12 Perigynia 3.5-4.0 mm long, nerved on both faces
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        5 Perigynia corky-thickened in the lower 1/3 to 1/2 at maturity.
                          13 Basal scales and sheaths purplish-tinted; perigynia ascending to spreading at maturity; [rare exotic]
                          13 Basal scales and sheaths light tan or brown; perigynia spreading or reflexed at maturity; [native species].
                            14 Leaves 2.2-4.6 mm wide; perigynia 3.3-5.6 mm long, beaks (1-) 1.4-1.8 mm long
                            14 Leaves 0.5-3 mm wide; perigynia not > than 4.0 long, beaks 0.3-1.2 mm long.
                              15 Beak of perigynium serrulate; pistillate scales acuminate-awned; perigynia mostly > 20 per spike
                              15 Beak of perigynium smooth or serrulate; perigynia (2-) 3-12 (-20) per spike.
                                16 Beak of perigynium smooth; pistillate scales acuminate, early deciduous.
                                  17 Average perigynium width ≥ 1.3 mm; average spongy portion of the perigynium ≥ 1.1 mm long; perigynium base distinctly nerved, bulging on the ventral surface, making the perigynium biconvex in cross-section; perigynium 2-2.5× as long as wide; perigynium gradually narrowed to a short beak; leaves 1-3 mm wide
                                  17 Average perigynium width < 1.3 mm; average spongy portion of the perigynium < 1.1 mm long; perigynium base nerveless, flattened on the ventral surface, making the perigynium planoconvex in cross-section; perigynium ca. 3× as long as wide; perigynium narrowed to a conspicuous beak; leaves 0.75-1.5 mm wide
                                16 Beak of perigynium serrulate; pistillate scales obtuse, persistent.
                                    18 Plants with creeping rhizomes, the culms arising scattered along the rhizome; perigynia 4-5× as long as wide
                                    18 Plants densely cespitose, the culms arising from the center of clump; perigynia 2-3× as long as wide.
                                       19 Widest leaves 0.9-1.7 mm wide; base of fertile culm 0.7-1.4 mm wide.
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                                         20 Base of perigynium cuneate to rounded; distance from base of perigynium to base of achene 0.1-0.5 mm; [primarily of the Mountains in our area on dry soils]
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                                         20 Base of perigynium rounded to truncate; distance from base of perigynium to base of achene 0.5-0.9 mm; [widespread in our area, soils typically mesic to wet]
                                       19 Widest leaves 1.7-3.0 mm wide; base of fertile culm 1.4-2.2 mm wide.
                                           21 Stigmas 0.03-0.06 mm thick, straight to slightly twisted; widest leaves < 2.0 mm wide; perigynia 3-7 (-8) per spike
                                           21 Stigmas 0.07-0.10 mm thick, mostly coiled; widest leaves > 1.7 mm wide; perigynia (6-) 7-14 (-20) per spike

Key to Carex, [26dd] Section 21 Careyanae: section Careyanae

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1 Basal sheaths purplish, sometimes mixed with brown.
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  2 Widest leaf blade 3-6 mm wide; peduncles of lateral spikes usually drooping
  2 Widest leaf blade 10-25 mm wide; peduncles of lateral spikes usually erect or spreading.
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    3 Bracts of middle and basal portions of culms with blades 2.1-9.2 cm long; perigynia 5.0-6.6 mm long; longest (per plant) lateral spike with 4-9 perigynia
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    3 Bracts of middle and basal portions of culms bladeless, or with blades 0.1-1.9 cm long; perigynia 3.7-4.9 mm long; longest (per plant) lateral spike with 9-13 perigynia
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1 Basal sheaths brownish, lacking any purple coloration.
      4 Widest leaf blade 11-25 mm wide; leaf blades of vegetative shoots 3.8-9.0 × as wide as bract leaves; bract blades from middle and basal portions of the culms 2.0-6.2 cm long; foliage glaucous
      4 Widest leaf blade 2-14 mm wide; leaf blades of vegetative shoots 1.0-3.5 × as wide as bract leaves; bract blades from middle and basal portions of the culms 4.5-24 cm long; foliage green or glaucous.
        5 Basalmost scale of each lateral spike sterile (lacking a perigynium) or subtending a staminate flower.
          6 Foliage usually bright green; longest (per plant) terminal spike 0.6-2.0 (-2.3) cm long; widest leaf blade 5.3-8.3 mm wide
          6 Foliage usually glaucous; longest (per plant) terminal spike (1.0-) 1.2-2.5 cm long; widest leaf blade 6.4-11.8 mm wide
        5 Basalmost scale of each lateral spike subtending a perigynium.
             7 Terminal spikes (1.0-) 1.2-2.7 mm wide; staminate scales acute, those from the middle region of the staminate spike 3.6-5.5 mm long; vegetative shoots shorter than or slightly taller than the culms, the tallest vegetative shoot 0.5-1.3 (-1.8)× as tall as the tallest culm.
               8 Terminal spike usually surpassing the bract blade of the distalmost lateral spike; longest (per plant) peduncle of terminal spike (6.3-) 8.1-15.9 cm long; widest leaf blade 2.0-2.9 (-3.5) mm wide; each perigynium face 7-10-nerved
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               8 Terminal spike usually surpassed by the bract blade of the distalmost lateral spike; longest (per plant) peduncle of terminal spike 0.9-7.2 (-11.4) cm long; widest leaf blade 2.7-4.5 (-5.3) mm wide; each perigynium face (8-) 11-15-nerved.
                 9 Perigynia 2.5-3.3 mm long, the apex barely excurved
                 9 Perigynia 3.2-4.2 mm long, the apex noticeably excurved
             7 Terminal spikes 0.6-1.4 (-1.6) mm wide; staminate scales obtuse, those from the middle region of the staminate spike 2.6-3.6 (-3.8) mm long; vegetative shoots much taller than the culms, the tallest vegetative shoot (1.4-) 1.7-3.7 (-4.9)× as tall as the tallest culm.
                   10 Perigynia spirally imbricate; longer lateral spikes with (6-) 8-13 perigynia; peduncles of proximal spikes usually erect, the longest (per plant) peduncle (7.0-) 15-42 (-49) mm long; bract blade of distalmost lateral spike 5.6-17 (-26) × as long as wide; loosely or densely cespitose; [primarily of the Coastal Plain in our area, though extending rarely into the Piedmont and Mountains]
                   10 Perigynia distichously imbricate; longer lateral spikes with 4-8 (-9) perigynia; peduncles of proximal spikes usually drooping or nodding, the longest (per plant) peduncle (28-) 44-84 (-91) mm long; bract blade of distalmost lateral spike (12-) 17-51 × as long as wide; densely cespitose; [primarily of the Mountains and Piedmont]

Key to Carex, [26ddd] Section 41 Pictae: section Pictae

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1 Plants monoecious, with 3-8 spikes per stem; leaf blades 4-8 mm wide, glaucous on the upper surface; [of the East Gulf Coastal Plain, east to sw. GA and Panhandle FL]
1 Plants dioecious, with a single unisexual spike per stem; leaf blades 2-4.5 mm wide, green on the upper surface; [of areas west of area, east to c. TN and nc. GA]

Key to Carex, [26e] Section 4.1 Dispermae: section Dispermae

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Key to Carex, [26ee] Section 22 Griseae: section Griseae (Oligocarpae)

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1 Culm bases brown.
  2 Leaf sheaths scabrous to hispidulous; perigynium beak (0.5-) 0.6-1.3 mm long
    3 Leaf blades, especially of overwintered leaves, glaucescent, papillose abaxially; perigynia (3.7-) 4.0-4.7 (-5.1) × 1.5-1.7 (-1.8) mm; longest terminal spikes (25-) 30-46 mm long; [of the Cumberland Plateau of n. AL]
    3 Leaf blades green, glabrous abaxially or sparsely hispidulous; perigynia (4.5-) 4.6- 5.6 (-6.2) × 1.9-2.2 (-2.3) mm; longest terminal spikes 14-34 (-42) mm long; [of ne. United States, south in our area to w. NC and w. VA]
  2 Leaf sheaths glabrous; perigynium beak 0-0.5 (-0.7) mm long
      4 Leaf blades glaucous; pistillate scales awnless or awn < 1 (-1.9) mm long.
        5 Perigynia (4.0-) 4.2-5.5 (-6.0) mm long; achene bodies 0.37-0.5× as long as the perigynia; pistillate spikes (5-) 5.7-8 (-9.6) mm wide; achene beak straight to bent less than 30° from the vertical
        5 Perigynia 3.2-4.5 (-4.7) mm; achene bodies 0.5-0.63 (-0.67)× as long as the perigynia; pistillate spikes (3.3-) 4.2-6.1 (-7.3) mm wide; achene beak usually bent 30-90° from vertical.
          6 Perigynia 3.2-4.0 (-4.1) mm long, (1.5-) 1.8-2.3 (-2.5)× as long as wide; longest pistillate spike with (14-) 19-45 (-65) flowers, densely flowered, with the ratio [mm of spike length/number of flowers] = (0.56-) 0.67-1.1 (1.3); longest peduncle of staminate spike 0.5-15 (-31) mm long
          6 Perigynia (3.7-) 3.9-4.5 (-4.7) mm long, (1.9-) 2.1-2.6 (-2.8)× as long as wide; longest pistillate spike with 11-25 (-28) flowers, rather loosely flowered, with the ratio [mm of spike length/number of flowers] = (0.97-) 1.0-1.3 (1.6); longest peduncle of staminate spike (1.5-) 7.5-37 (-62) mm long
      4 Leaf blades deep or light green; pistillate scales usually with awns (0-) 1.2-3.7 (-6) mm long.
             7 Peduncles of lateral spikes scaberulous; perigynia (6-) 18-37 (-86) per spike; perigynia (2.5-) 2.8-3.6 (-4.3) mm long, 17-25-veined
             7 Peduncles of lateral spikes glabrous or scaberulous; perigynia (3-) 5-16 (-19) per spike; perigynia (3.6-) 4-5 (-5.5) mm long, 40-65-veined
               8 Widest leaf blades 2.6-4.0 mm wide; ligules of proximal bracts 0.4-1.8 (-3.6) mm long; perigynium apex bent; achene beaks bent
               8 Widest leaf blades (3.7-) 4.2-8.2 (-9.1) mm wide; ligules of proximal bracts (1.8-) 4.0-10.7 (-12.9) mm long; perigynium apex straight; achene beaks straight.
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                 9 Perigynia obtusely triangular in cross section, (2.2-) 2.5-3.1 × as long as wide, 1.5-1.9 (-2.2) mm wide; achenes (1.3-) 1.5-1.7 (-1.8) mm wide; achene stipes (0.3-) 0.4-0.6 mm long
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                 9 Perigynia orbicular to suborbicular in cross section, 1.8-2.3 (-2.6)× as long as wide, (1.8-) 2-2.6 mm wide; achenes 1.7-2.1 (-2.2) mm wide; achene stipes (0.2-) 0.3-0.4 (-0.5) mm long
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1 Culm bases purple-red
                   10 Plants not cespitose; rhizome internodes 2-3.4 mm thick; terminal spikes (2.8-) 3.3-4.5 (-5.4) mm wide, usually much exceeding the distal bract
                   10 Plants cespitose; rhizome internodes 1.2-2.2 mm thick; terminal spikes (0.9-) 1.3-2.9 (-3.1) mm wide, usually much exceeded by the distal bract
                     11 Perigynia spirally imbricate; proximal bracts with sheaths loose; ligules (0.9-) 2-12.9 mm
                       12 Culm bases with purple-red to (3.4-) 4.0-7.3 cm high; widest leaf blades 2.4-4.0 (-5.3) mm wide; achene stipes 0.6-0.8 (-0.9) mm long
                       12 Culm bases with purple-red to 0.3-2.4 (-7.3) cm high; widest leaf blades 3.3-8.0 (-9.1) mm wide; achene stipes (0.2-) 0.3-0.6 mm long.
                          13 Perigynia (1.8-) 2.0-2.6 mm wide, orbicular to suborbicular in cross section; achene bodies (2.6-) 3.1-3.5 (-3.7) mm long; achene stipes (0.2-) 0.3-0.4 (-0.5) mm; achene bodies 4.8-9.7 (-12)× as long as the stipes
                          13 Perigynia 1.5-2.3 (-2.4) mm wide, obtusely triangular in cross section; achene bodies 1.8-2.3 (-2.4) mm long; achene stipes (0.3-) 0.4-0.6 mm; achene bodies 3.2-5.8 (-7.3)× as long as the stipes.
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                            14 Perigynia 4.2-5.0 (-5.2) × 1.5-1.9 (-2.2) mm, (2.2-) 2.5-3.1× as long as wide; achene bodies broadly obovoid to oblong-obovoid, widest at a point 0.55-0.67 (-0.70) from base to tip of body
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                            14 Perigynia (3.6-) 3.9-4.5 (-4.7) × (1.7-) 1.8-2.3 (-2.4) mm, 1.8-2.3 (-2.5)× as long as wide; achene bodies broadly obdeltoid-obovoid, widest at a point (0.6-) 0.65-0.80 from base to tip of body
                     11 Perigynia distichously imbricate; proximal bracts with sheaths tight; ligules 4-4.9 (-9.6) mm (to 2.2 mm in C. bulbostylis).
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                              15 Perigynia much inflated, orbicular or suborbicular in cross section, (1.8-) 2.0-2.5 (-2.8) mm wide, 1.6-2.0 (-2.1)× as long as wide
                              15 Perigynia tightly enveloping achene or slightly inflated, obtusely triangular in cross section, 1.4-2.1 (-2.3) mm wide, (1.7-) 2.1-3.3× as long as wide.
                                16 Plants loosely cespitose; longer rhizome internodes 7-58 mm long
                                16 Plants densely cespitose; longer rhizomes internodes 0.2-6 (-8) mm long.
                                  17 Proximal bracts with bases of blades white between veins (most easily seen on abaxial surface)
                                  17 Proximal bracts with bases of blades uniformly green
                                    18 Perigynia (1.7-) 2.1-2.6× as long as wide, apex usually abruptly contracted; beak (0.3-) 0.5-1.2 mm long; longest lateral spike with 2-8 (-10) perigynia (including undeveloped or aborted ones)
                                       19 Proximalmost spike usually considerably beyond base of culm; longest vegetative shoot 0.88-1.4× as long as the longest culm; proximal bracts with sheath front convex and elongated (0.8-) 1.1-4.0 mm beyond apex
                                       19 Proximalmost spike usually basal; longest vegetative shoot (0.8-) 1.4-4.4× as tall as the culms; proximal bracts with sheath front apices concave or truncate.
                                         20 Culm bases with purple-red extending 2.7-5.2 (-5.6) cm; bodies of pistillate scales (2.2-) 2.5-3.0 mm long; achene beaks (0.1-) 0.2-0.3 mm long
                                         20 Culm bases with purple-red extending (3.7-) 4.7-11.7 cm; bodies of pistillate scales 1.5-2.1 (-2.5) mm long; achene beaks 0.05-0.10 (-0.15) mm long
                                    18 Perigynia (2.4-) 2.5-3.3× as long as wide, apex gradually tapering; beakless or the beak 0.1-0.4 mm; longest lateral spike with (5-) 7-14 perigynia (including undeveloped or aborted ones)
                                           21 Perigynia (1.9-) 2.0-2.3× as long as the achene bodies; achene beaks (0.3-) 0.4-0.7 mm long
                                           21 Perigynia 1.7-2.0× as long as the achene bodies; achene beaks 0.1-0.3 (-0.4) mm long.
                                             22 Longest (per plant) peduncle of terminal spike 0.9-3.2 (-6.8) cm long; two distalmost lateral spikes usually overlapping; longest vegetative shoot 1.4-2.2× as tall as the longest culm
                                             22 Longest (per plant) peduncle of terminal spike (2.2-) 5.1-8.9 (-10.4) cm long; two distalmost lateral spikes usually widely separate or occasionally overlapping; longest vegetative shoot 0.5-1.3× as tall as the longest culm

Key to Carex, [26f] Section 4.2 Chordorrhizae: section Chordorrhizae

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Key to Carex, [26ff] Section 23 Hymenochlaenae: section Hymenochlaenae -- Key to Groups

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1 Terminal spike staminate; lateral spikes staminate, androgynous, or pistillate; base of culms tan, brown, or ivory.
  2 Plants without rhizomes or with very short ones, densely cespitose
  2 Plants with short-creeping rhizomes, loosely cespitose or colonial
1 Terminal spike staminate or gynecandrous; lateral spikes pistillate, gynecandrous or rarely distal spike staminate; base of culms usually covered with dark maroon bladeless sheaths (often missing or very short in C. prasina).
    3 Perigynia 2-ribbed but otherwise veinless or nearly so, green to yellow at maturity
    3 Perigynia 2-ribbed and veined between ribs, often conspicuously so, green to olive-green at maturity, usually red dotted.
      4 Perigynia fusiform to narrowly lance-ovoid, > 5 mm long, including the elongate beak; leaves generally < 5 mm wide; leaf sheaths usually glabrous, at least on back
      4 Perigynia ovoid-oblong to lance-ovoid, 2-6 mm (mostly < 5 mm long) tapering to a beak shorter than the body or beakless; leaves 2.5-12 mm wide; leaf sheaths glabrous or pubescent.
        5 Terminal spike usually gynecandrous, rarely staminate
        5 Terminal spike usually staminate, rarely gynecandrous.
          6 Lateral pistillate spikes erect at maturity, narrowly oblong to cylindric, to 25 × 2.5-9 mm, on stiff peduncles
          6 Lateral pistillate spikes drooping at maturity, short cylindric to linear, 8-80 × 3-5 mm, on slender arching peduncles

Key to Carex, [26ff] Section 23a Hymenochlaenae: section Hymenochlaenae (the "Longirostres" group)

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1 Perigynia several-nerved, the beak much shorter than the body; basal sheath not conspicuously fibrous
1 Perigynia 2-ribbed (otherwise nearly nerveless), the beak about as long as the body; basal sheath conspicuously fibrous

Key to Carex, [26ff] Section 23b Hymenochlaenae: section Hymenochlaenae (the "Gracillimae" group)

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1 Lowest pistillate bract auriculate but not sheathing; terminal spike normally staminate (rarely with a few perigynia terminally); leaf blades 1-2 mm wide; basal sheaths purplish or red; [of cliffs and rock outcrops at moderate to high elevations in the Mountains]
1 Lowest pistillate bract sheathing (the sheath short in C. prasina); terminal spike normally gynecandrous, rarely merely staminate (often merely staminate in C. prasina); leaf blades 1.5-7 mm wide; basal sheaths purplish or red (brownish or greenish in C. prasina); [of various habitats, only rarely as above].
  2 Perigynia strongly trigonous, the lateral ribs at the angles, broadest below the middle; basal sheaths brownish or greenish; leaf sheaths glabrous on the hyaline ventral portion
  2 Perigynia terete to obscurely trigonous, the lateral ribs not at the angles, broadest near the middle; basal sheaths purplish or red; leaf sheaths pubescent on the hyaline ventral portion (glabrous in C. gracillima).
    3 Perigynia densely white-hirsute; achenes brown with dark red spots
    3 Perigynia glabrous; achenes without dark red spots.
      4 Leaf sheaths glabrous on the hyaline ventral portion; larger leaves 3-9 mm wide
      4 Leaf sheaths pubescent on the hyaline ventral portion; larger leaves 1.5-6 mm wide.
        5 Perigynia 2.5-3.0 mm long, 0.9-1.2 mm wide; perigynium beaks absent or very short, the orifice entire; leaf blades1.5-2.5 mm wide
        5 Perigynia 3.0-6.0 mm long, 1.4-2.0 mm wide; perigynium beaks very short to short, the orifice bidentate; leaf blades 2-6 mm wide.
          6 Perigynia 3.0-4.0 mm long, 1.5-1.75 mm wide; leaves 2-4 mm wide
          6 Perigynia 3.5-6.0 mm long, 1.75-2.5 mm wide; leaves 3-8 mm wide.
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             7 Upper pistillate scales awned (awn 2.5-3 mm long); perigynia 4.5-6.0 mm long, 2.0-2.5 mm wide
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             7 Upper pistillate scales acuminate; perigynia 3.5-4.6 mm long; leaves 3-5 mm wide.
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               8 All spikes gynecandrous, the lateral spikes with at least 1 staminate flower at base; peduncles longer than the pistillate spikes
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               8 Only the terminal spike gynecandrous, the lateral pistillate; peduncles shorter than the pistillate spikes

Key to Carex, [26ff] Section 23c Hymenochlaenae: section Hymenochlaenae (the "Sylvaticae" group)

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1 Achene sessile in the base of the perigynium; perigynia 3.2-6 mm long; sterile shoots with leaves 5-10 mm wide; [either exotic and rarely naturalized in our area, or native and rare].
  2 Perigynia 3.2-4.8 mm long, abruptly narrowed to a short stipe; [native, of northern hardwoods forests in the Mountains of NC and VA]
  2 Perigynia 5-6 mm long, sessile; [exotic, rarely naturalized in our area]
1 Achene on a stipe 0.5-1.5 mm long; perigynia (4.5-) 5.6-8.0 (-10) mm long; sterile shoots with leaves 2-8 mm wide; [native, collectively common and widespread in our area].
    3 Internodes between the perigynia mostly 1.0-1.5 mm; sheaths of the pistillate bracts puberulent at the mouth.
      4 Perigynia glabrous, (5.2-) avg. 6.2 (-7.7) mm long
      4 Perigynia puberulent, (6.4-) avg. 7.2 (-8.1) mm long
    3 Internodes between the perigynia mostly 2.0-4.0 (-6.0) mm; sheaths of the pistillate bracts glabrous at the mouth.
        5 Perigynia puberulent, (5-) avg. 7 (-9) mm long; pistillate scales usually with the midrib excurrent as a short awn
        5 Perigynia glabrous, (4.5-) avg. 5.6-7 (-10) mm long; pistillate scales usually with the midrib terminating below the apex, not excurrent.
          6 Perigynia (6-) avg. 7.0 (-10) mm long, broadest below the middle, tapering with straight or slightly convex sides to a conspicuous beak with a hyaline tip; pistillate scales obtuse; [of swamps, bogs, and other moist to wet habitats, nearly throughout our area]
          6 Perigynia (4.5-) avg. 5.6 (-7) mm long, broadest near the middle, tapering with concave sides to a short beak lacking a hyaline tip; pistillate scales acute to acuminate (the lowest sometimes aristate); [of dry to moist upland forests and openings in the Mountains]

Key to Carex, [26fff] Section 42 Mitratae: section Mitratae (Praecoces)

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1 Plant cespitose; lowest inflorescence bract longer than the inflorescence; pistillate scales with an awn 1.0-3.5 mm long
1 Plant from creeping rhizomes; lowest inflorescence bract much shorter than the inflorescence; pistillate scales acute to cuspidate

Key to Carex, [26g] Section 4.3 Physoglochin: section Physoglochin

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1 One species
1 One species

Key to Carex, [26ggg] Section 43 Albae: section Albae

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1 One species

Key to Carex, [26h] Section 5 Holarrhenae: section Holarrhenae (Intermediae)

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1 One species
1 One species

Key to Carex, [26i] Section 6 Divisae: section Divisae

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1 Culm angles smooth below the inflorescence; rhizomes slender, 0.6-1.8 mm thick, shoots often arising 2-several in a cluster and many nodes without shoots
1 Culm angles at least slightly scabrous below inflorescence; rhizomes coarse, 1.8-3 mm thick, typically with long unbranched segments from which shoots arise singly every few nodes.
  2 Beak of the perigynium 1/5 to 1/3 as long as the body; spikes 2-7 (-10); [exotic, naturalized primarily in brackish to salty coastal habitats]
  2 Beak of the perigynium 1/3 to 1/2 as long as the body; spikes 5-15; [exotic, naturalized primarily inland along highways treated with salt]

Key to Carex, [26ii] Section 24 Porocystis: section Porocystis (Virescentes)

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1 Terminal spike staminate (rarely gynecandrous, with fewer than 25% of the flowers pistillate)
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1 Terminal spike gynecandrous (and with > 30% of the flowers pistillate).
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Show caption*© Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman
  2 Perigynia densely pubescent; larger lateral spikes 2-4 mm wide; ligules longer than wide.
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    3 Terminal spikes 5-15 (-20) mm long; anthers 0.7-1.3 (-1.6) mm long
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    3 Terminal spikes (18-) 20-35 mm long; anthers (1.0-) 1.6-2.0 (-2.8) mm long
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  2 Perigynia glabrous, or minutely papillose, or with few scattered hairs; larger lateral spikes (3.5-) 4-8 mm wide; ligules as wide as long.
      4 Perigynia papillose, with a short but definite beak, 2.5-4.0 mm long; anthers 2.5-3.5 mm long; pistillate scales about equal to perigynia or slightly longer; pistillate spikes 6-10 mm wide
      4 Perigynia not papillose, beakless or with a short but definite beak [C. caroliniana], 2.0-3.5 mm long; anthers 1.3-2.5 mm long; pistillate scales usually much shorter than perigynia; pistillate spikes 4-7 mm wide.
        5 Perigynia with a short but distinct beak, when mature more-or-less rounded in ×-section and with no faces flattish; blades glabrous or glabrate
        5 Perigynia beakless, when mature more-or-less triangular in ×-section (or hemispheric) and with the inner face flattish, blades glabrous or glabrate [C. complanata] or densely hirtellous [C. hirsutella].
          6 Blades glabrous or glabrate, especially on lower surface, sheaths glabrate to pubescent (if so, pubescence dense only in summit region); [mostly Coastal Plain and Piedmont]
          6 Blades and sheaths densely hirtellous throughout; [mostly Coastal Plain, Piedmont, and Mountains]

Key to Carex, [26j] Section 7 Ammoglochin: section Ammoglochin (Arenariae)

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1 Perigynia thin-margined and prominently winged at base of beak; pistillate scales usually longer than perigynia; terminal spike usually staminate; [exotic in maritime situations]
1 Perigynia thin-margined, lacking a prominent, expanded wing; pistillate scales shorter than to nearly equaling the perigynia; terminal spike usually pistillate or androgynous; native, inland]

Key to Carex, [26k] Section 8 Macrocephalae: section Macrocephalae

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1 One species

Key to Carex, [26kk] Section 25 Anomalae: section Anomalae

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1 One species

Key to Carex, [26kkk] Section 44 Phyllostachyae: section Phyllostachyae

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1 Widest leaves (4.1-) 6-15 mm wide; leaves strongly glaucous; [AR and OK]
1 Widest leaves (1-) 2-5.5 mm wide; leaves green or slightly glaucous; [collectively widespread].
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  2 Lower pistillate scales (2.0-) 2.5-6.5 mm wide, wrapping around and nearly concealing the perigynium; staminate flowers 2-4 per spike
  2 Lower pistillate scales (2.0-) 2.5-6.5 m(0.9-) 1.2-2.5 (-3.0) mm wide, no more than 1.5× as wide as the perigynium, the margins spreading, and not concealing the perigynium; staminate flowers (2-) 5-25 per spike.
    3 Achenes subglobose, 1-1.5× as long as wide; staminate scales more or less truncate.
      4 Tallest culm 3.2-9.1 cm high, 15-32% of plant height; terminal spike with 4-8 perigynia; wider leaves with hyaline margins 0.05-0.2 mm wide; hyaline margins of distal pistillate scales 0.05-0.3 mm wide; perigynium beak 30-38% (-43%) of perigynium length; [of calcareous glades in w. VA and north and west of our area]
      4 Tallest culm 9.0-41 cm high, 39-86% of plant height; terminal spike with 1-4 perigynia; wider leaves with green margins; hyaline margins of distal pistillate scales 0.3-0.7 mm wide; perigynium beak 34-53% of perigynium length; [of rich forests or rocky calcareous glades and woodlands].
        5 Longest (per plant) staminate portion of terminal spike (4.9-) 5.8-13.5 mm long; proximalmost staminate scale in terminal spike 1.1-1.8 (-2.1) mm long, 13-26 (-35)% of length of staminate portion of terminal spike; perigynium beaks (1.9-) 2.3-3.9 mm long, 39-53% of perigynium length; shoot bases lacking red-purple; [of rich mesic forests widespread in our area, especially VA]
        5 Longest (per plant) staminate portion of terminal spike 3.4-5.6 (-6.2) mm long; proximalmost staminate scale in terminal spike (1.9-) 2.1-3.3 mm long, (35-) 44-77% of length of staminate portion of terminal spike; perigynium beaks 1.4-2.3 (-2.5) mm long, 34-44% of perigynium length; shoot bases tinged with reddish-purple; [of c. TN and c. KY and westward]
    3 Achenes ellipsoid, 1.5-2.0× as long as wide; staminate scales obtuse to acute.
          6 Tallest culm 0.18-0.38× as tall as plant; perigynia (7.0-) 7.5-10.8 mm long; perigynium beaks (3.6-) 4.1-6.4 mm long; culms erect; peduncles usually erect to spreading
          6 Tallest culm 0.41-0.87× as tall as plant; perigynia 4.5-8.0 mm long; perigynium beaks 1.7-4.3 mm long; culms erect to spreading; peduncles usually widely spreading to nodding.
             7 Longest staminate portion of terminal spikes 12.7-25.6 mm long; perigynia 5.8-8.0 mm long; perigynium beaks 2.5-4.3 mm long; achenes (2.4-) 2.6-3.4 mm long
             7 Longest staminate portion of terminal spikes 4.9-5.7 (-6.5) mm long; perigynia 4.5-5.7 (-6.5) mm long; perigynium beaks 1.7-2.6 (-2.8) mm long; achenes 1.8-2.6 mm long

Key to Carex, [26ll] Section 26 Hallerianae: section Hallerianae

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1 Perigynia 3-4.5 mm long, the lower shorter than their subtending scales; culms often with basal spikes
1 Perigynia 4-6 mm long, all exceeding their subtending scales; culms without basal spikes.
  2 Perigynia densely white-villous apically, glabrous basally; achene body 2.0-2.7 mm long, long-stipitate
  2 Perigynia puberulent throughout; achene body 3.0-3.3 mm long, sessile

Key to Carex, [26lll] Section 45 Firmiculmes: section Firmiculmes

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1 One species; [native to w. NA, waif]
1 One species; [native to w. NA, waif]

Key to Carex, [26m] Section 9 Glareosae: section Glareosae (Heleonastes)

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1 Spikes (1-) 2 (-3); perigynia 1-5 per spike, 2.5-4 mm long.
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Show caption*© Nate Martineau, some rights reserved (CC BY-NC), uploaded by Nate Martineau
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  2 Leaves 0.3-0.8 mm wide, filiform-involute; ligules 0.3-0.8 (-1.2) mm long; inflorescences 14-32 mm long; spikes 2-3 per inflorescence; terminal spike with 1-3 perigynia per spike; [south to PA and s. NJ]
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Show caption*© Nate Martineau, some rights reserved (CC BY-NC), uploaded by Nate Martineau
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Show caption*© Nate Martineau, some rights reserved (CC BY-NC), uploaded by Nate Martineau
  2 Leaves 0.8-1.9 mm wide, flat or thinly M-shaped; ligules 0.5-1.9 mm long; inflorescences (14-) 23-55 mm long; spikes (2-) 3-4 per inflorescence; terminal spike with (1-) 2-6 perigynia per spike; [south to w. NC]
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1 Spikes 4-15; perigynia 5-30 per spike; 1.7-2.5 mm long.
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    3 Perigynia 5-10 (-15) per spike; perigynium without ventral nerves (or the nerves very obscure); spike at maturity somewhat bristly appearing in silhouette because of the perigynium beaks
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    3 Perigynia (10-) 15-30 per spike; perigynium ventrally nerved; spike at maturity nearly smooth in silhouette (the perigynium beaks strongly appressed)
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      4 Culms 15-60 cm tall; inflorescence 3-5 (-7) cm long, all but the lowest spikes approximate, the lowest spikes 0.5-2.5 cm apart
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Show caption*© Bruce Sorrie
      4 Culms 30-90 cm tall; inflorescences 6-12 (-15) cm long, the lower and middle spikes well-spaced, the lowest spikes 2-5 cm apart

Key to Carex, [26mmm] Section 46 Leptocephalae: section Leptocephalae (Polytrichoidae)

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1 Perigynia 3.4-4.9 (-5.4) mm long; pistillate scales whitish
1 Perigynia 2.5-3.5 mm long; pistillate scales pale brown, with green midrib

Key to Carex, [26n] Section 10 Deweyanae: section Deweyanae

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1 Perigynia 2.3-3.9 (-4.2)× as long as wide, 0-5 (7)-veined abaxially (the veins extending unbroken from the perigynium base to the base of the perigynium beak); achenes 1.2-1.8× as long as wide; widest leaf blade (2.2-) 2.4-5.9 mm wide; [of uplands, south to n. NJ, n. PA, n. OH, n. IL]
1 Perigynia (3.3-) 4.1-6.7× as long as wide, (3-) 4-8-veined abaxially (the veins extending unbroken from the perigynium base to the base of the perigynium beak); achenes 1.9-2.9 × as long as wide; widest leaf blade 1.3-4.4 mm wide; [of wetlands, collectively widespread].
  2 Widest leaf (1.3-) 1.5-2.9 (-3.1) mm wide; culms (0.5-) 0.6-1.0 (-1.1) mm thick at mid-height; plant densely to loosely cespitose, the rhizome internodes 0.2-20 mm long; [of swamp forests and other wetlands, widespread in our area]
  2 Widest leaf 2.8-4.4 mm wide; culms 1.0-1.6 mm thick at mid-height; plants densely cespitose, the rhizome internodes 0.2-1.0 (-8.5) mm long; [of seeps and bogs in the Blue Ridge and Blue Ridge Escarpment region of sw. VA, w. NC, e. TN, and nw. SC]

Key to Carex, [26nn] Section 27 Hirtifoliae: section Hirtifoliae

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1 One species
1 One species

Key to Carex, [26o] Section 11 Stellulatae: section Stellulatae

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1 Spikes usually solitary; leaves involute; anthers 2.0-3.6 mm long; [mucky bogs, south to DE and e. MD; disjunct in sc. NC and s. AL and s. MS]
1 Spikes 2-8; leaves flat or folded; anthers 0.6-2.2 (-2.4) mm long.
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  2 Perigynium beak smooth-margined (use at least 10× magnification)
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  2 Perigynium beak serrulate on margin (use at least 10× magnification).
    3 Widest leaves 2.8-5.0 mm wide.
      4 Lower perigynia of spikes mostly 1.1-1.7× as long as wide, mostly 2.1-3.0 mm wide
      4 Lower perigynia of spikes (1.5-) 1.7-3× as long as wide, mostly 1.2-2.0 mm wide.
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Show caption*© Gary P. Fleming
        5 Inflorescences mostly 3-8.5 cm long, the lowermost 2 spikes separated by 10-40 mm; [ sw. VA south to nw. SC and n. GA]
        5 Inflorescences mostly 1.5-3 cm long, the lowermost 2 spikes separated by 1.3-9.5 mm; [south to n. PA]
    3 Widest leaves 0.8-2.7 mm wide.
          6 Terminal spikes entirely staminate; anthers (1.0-) 1.2-2.2 (-2.4) mm long
          6 Terminal spikes partly or entirely pistillate; anthers 0.6-2.2 (-2.4) m long.
             7 Terminal spikes without a distinct narrowed base of staminate scales, the staminate portion < 1 mm long
             7 Terminal spikes with a distinct narrowed base of staminate scales 1.0-16.5 mm long.
               8 Lower perigynia 2.0-3.0 mm wide
               8 Lower perigynia 0.9-2.0 mm wide.
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                 9 Lower perigynia mostly 2.8-4.8 mm long; lower perigynia (1.7-) 1.8-3.6× as long as wide; perigynia beaks 0.95-2.0 mm long, mostly 0.45-0.85× as long as the perigynium body
                 9 Lower perigynia mostly 1.9-3.0 mm long; lower perigynia 1.0-2.0 (-2.2)× as long as wide; perigynia beaks 0.4-0.95 mm long, mostly 0.2-0.5× as long as the perigynium body.
                   10 Perigynia mostly nerveless over the achene on the adaxial surface; beak of perigynia conspicuously setulose-serrulate; perigynia often more-or-less convexly tapered from widest point to the beak, thus forming a weak shoulder; [of calcareous sites, in our area restricted to the Mountains of VA]
                   10 Perigynia mostly 1-10-nerved over the achene on the adaxial surface; beak of perigynia more sparsely serrulate, with definite spaces between the often single teeth; perigynia more-or-less cuneate or concavely tapered from widest point to the beak, not forming a shoulder; [of a variety of situations, not generally calcareous].
                     11 Widest leaves 1.6-2.7 mm wide; infructescence mostly 18-45 mm long; [widespread in our area]
                     11 Widest leaves 0.6-1.6 mm wide; infructescence mostly 8-20 mm long; [primarily of the Coastal Plain in our area, widely scattered elsewhere]

Key to Carex, [26oo] Section 28 Paludosae: section Paludosae

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1 Perigynium body pubescent.
  2 Culms central, with the withered remains of the previous year’s leaves at the base; basal sheaths of fertile culms not at all or only slightly reddened; [of the Coastal Plain]
  2 Culms lateral, with bladeless sheaths at the base; basal sheaths strongly reddened; [collectively widespread in our area].
    3 Beak of the perigynium soft, translucent, the teeth obscure; peduncle of staminate spike 0.2-2 cm long; [of the Piedmont and Coastal Plain in our area]
    3 Beak of the perigynium stiff, opaque, the teeth well-developed; peduncle of staminate spike (0.8-) 2-9 cm long; [of the Mountains in our area].
      4 Leaves folded along the midrib, appearing 0.7-2.0 (-2.2) mm wide; culms obtusely trigonous, usually smooth; base of pistillate bracts often auriculate, forming a V-shaped mouth; middle staminate scales narrowly acute
      4 Leaves more-or-less flat or M-shaped, (1.8-) 2.2-4.5 (-6) mm wide; culms acutely trigonous, often scabrous on the angles; base of pistillate bract with a short, truncated process at mouth; middle staminate scales obtuse and short-awned, or acute
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1 Perigynium body glabrous.
        5 Widest leaves 1.5-5 (-6) mm wide; culms 8-90 cm tall; inflorescences 2.5-35 (45) cm long.
          6 Inflorescence rachis with rounded, smooth angles; lowermost pistillate spikes usually strongly overlapping; [introduced, in coastal sands]
          6 Inflorescence rachis with sharp, scabrous angles; lowermost pistillate spikes overlapping not at all or slightly; [native, in acidic Coastal Plain wetlands]
        5 Widest leaves (4-) 5.5-15 (-21) mm wide; culms 40-135 cm tall; inflorescences 15-60 cm long.
             7 Perigynia 3.0-4.5 mm long; [exotic species]
             7 Perigynia 4.8-7.8 mm long; [native species].
               8 Longest ligules 2-10 (-12) mm long, < 2 × as long as wide; culms central, with the withered remains of the previous year’s leaves at the base; perigynia obscurely 10-15-veined; [of the Coastal Plain]
               8 Longest ligules 13-40 (-56) mm long, much longer than wide; culms lateral, with bladeless sheaths at the base; perigynia usually strongly 14-28-veined; [of the Mountains in our area]

Key to Carex, [26pp] Section 29 Carex: section Carex

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1 Beaks of perigynia glabrous or with scattered spreading hairs on main veins; leaf blades finely papillose on the lower surface (and also usually long-pubescent); vegetative culms hollow, spongy (flattened when pressed)
1 Beaks of perigynia pubescent or scabrous both on and between main veins; leaf blades glabrous or pubescent abaxially, but not papillose; vegetative culms hard.
  2 Leaf blades pubescent; [rare introduction]
  2 Leaf blades glabrous; [native].
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    3 Perigynia glabrous or scabrous on main veins, 4.8-8.4 mm long
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    3 Perigynia pubescent, 6-11.5 mm long

Key to Carex, [26q] Section 12 Ovales: section Ovales

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1 Pistillate scales uniformly as long as or longer than the mature perigynia, usually concealing the beaks (though not necessarily the bodies), apex obtuse to acuminate, not awned.
  2 Perigynium beak cylindric, unwinged, lacking serrations for ca. 0.4 mm below the apex
  2 Perigynium beak flattened, ciliate-serrulate all the way to the apex.
    3 Pistillate scales as wide as and essentially covering perigynia bodies
    3 Pistillate scales usually distinctly narrower than perigynia bodies.
      4 Principal leaves stiff, more-or-less glaucous, often bearing auricles at the base, the summit of the sheaths truncate, prolonged 1-4 mm beyond the collar; flat margins of perigynia 0.5-0.8 mm wide; achenes 1.0-1.2 mm wide; [of maritime dunes and shores]
      4 Principal leaves pliable, green, almost always without auricles, the summit of the sheaths U-shaped, only slightly prolonged beyond the collar; flat margins of perigynia 0.2-0.6 mm wide; achenes 1.0-1.7 mm wide; [of inland, non-maritime habitats].
        5 Perigynia ascending to spreading, strongly and evenly veined on the adaxial face, finely granular-papillose; spikes (3-) 7-15, the uppermost usually densely aggregated
        5 Perigynia erect-ascending, often veinless on the adaxial face or with a few veins of unequal strength, smooth; spikes 3-7 (-11), the uppermost often more-or-less separated
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1 Pistillate scales (excluding the awns, if present) shorter than the perigynia at least in the middle portions of the spikes, the apical portion of the pistillate scales narrower than the perigynia beaks and not completely covering them, the apex awned in some species.
          6 Pistillate scales in middle or lower portions of spikes with apex acuminate with subulate or awned tip.
             7 Perigynia 2.6-4.0× as long as wide, the bodies lanceolate, 1.2-2.0 mm wide
               8 Perigynia 0.9-1.2 mm wide; achenes 0.6-0.8 mm wide; inflorescences dense, the lowermost internode 2-3 (-5) mm long
               8 Perigynia 1.2-2 mm wide; achenes 0.7-1.1 mm wide; inflorescences dense to open, the lowermost internode 2-17 mm long.
                 9 Inflorescences nodding or flexuous, spikes well separated; pistillate scales acute; perigynia spreading
                 9 Inflorescences dense or open, spikes usually overlapping; pistillate scales acuminate; perigynia usually ascending
             7 Perigynia < 2.5× as long as wide, the bodies lance-ovate, ovate, broadly elliptic, orbiculate, or obovate, 1.8-3.9 mm wide.
                   10 Perigynia (5.8-) 6.0-7.1 mm at longest; perigynium beak 2-2.8 mm long; pistillate scales with apex white-hyaline, acuminate-awned, fragile, membranaceous, and often curled, midvein not extending to tip
                   10 Perigynia (2.3-) 2.5-5.9 (-6.3) mm at longest; perigynium beak 0.85-2.2 (-2.5) mm long; pistillate scales with apex firm, greenish to reddish brown, straight, midvein extending to tip.
                     11 Perigynium body obovate, often with conspicuous “shoulders”; leaves 2.5-6 mm at widest
                     11 Perigynium body elliptic, suborbiculate, or weakly obovate; leaves 1-3 (-4.2) mm at widest.
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                       12 Perigynium body cuneately tapered to the base, the body of the perigynium more-or-less diamond-shaped; inflorescences dense, stiffly erect, with 3-5 spikes
                       12 Perigynium body convexly tapered to the base (the base rounded), the body of the perigynium ovate, elliptic, orbiculate, or weakly obovate; inflorescences dense and erect or open and nodding, with 3-11 spikes.
                          13 Scales with white-hyaline or pale yellowish margins; perigynia greenish to straw-colored or pale brown, (2.3-) 2.5-4.0 (-4.2) mm long, often indistinctly 0-4 (-6) veined on the outer side
                          13 Scales with reddish-brown margins; perigynia reddish-brown, (3.8-) 4.0-5.5 mm long, conspicuously veined on the outer side with 5 or more veins.
                            14 Beaks ascending, < ½ the length of the lance-ovate to weakly obovate perigynium body; lateral spikes with acute staminate bases mostly < 2 mm long; [of tidal marshes]
                            14 Beaks widely spreading, > ½ the length of the suborbicular perigynium body; lateral spikes with tapered staminate bases 2-6 mm long; [of freshwater wetlands]
          6 Pistillate scales with apex obtuse, acute, or acuminate (but not subulate or awned).
                              15 Perigynia < 2 mm wide.
                                16 Perigynia thin, often not winged to the base; leaf sheaths somewhat expanded toward the apex, bearing narrow wings continuous with the midvein and the edges of the leaf blade; leaves 3-7.5 mm wide; vegetative shoots tall, conspicuous, with numerous leaves spaced along the upper half of the culm.
                                  17 Lower perigynia of each spike spreading or recurved (at an angle of > 80 degrees); spikes globose; pistillate scales hidden, 1.6-2.3 mm long
                                  17 Lower perigynia of each spike appressed-ascending to somewhat spreading (at a 30-75 degree angle); spikes subglobose to ovate-oblong; pistillate scales evident, 2.0-3.0 mm long.
                                    18 Inflorescences usually flexible, nodding at the tip, the lower spikes usually separated; perigynia usually 15-40, spreading at a 40-75 degree angle to the spike axis; leaf sheaths firm or friable at the summit
                                    18 Inflorescences straight and stiff, the lower spikes overlapping; perigynia usually > 40, appressed-ascending at a 30-40 degree angle to the spike axis; leaf sheaths firm at the summit.
                                       19 Perigynia 3.0-4.0 mm long, 2.2-2.8 (-3) × as long as wide
                                       19 Perigynia (3.3-) 3.6-5.4 mm long, 3-5 × as long as wide
                                16 Perigynia thick, winged to the base; leaf sheaths with more-or-less rounded edges, not distinctly expanded toward the apex; leaves 1-4.5 mm wide (except in C. normalis); vegetative shoots usually inconspicuous, with relatively few leaves clustered at the tip.
                                         20 Perigynia (2.5-) 2.6-4 × as long as wide, the body lanceolate, distance from beak tip to top of achene 2.2-5 mm
                                           21 Perigynia 0.9-1.2 mm wide; achenes 0.6-0.8 mm wide; inflorescences dense, the lowermost internode 2-3 (-5) mm long
                                           21 Perigynia 1.2-2 mm wide; achenes 0.7-1.1 mm wide; inflorescences dense to open, the lowermost internode 2-17 mm long.
                                             22 Inflorescences nodding or flexuous, spikes well separated; pistillate scales acute; perigynia spreading
                                             22 Inflorescences dense or open, spikes usually overlapping; pistillate scales acuminate; perigynia usually ascending
                                         20 Perigynia < 2.5 × as long as wide, the body obovate, orbiculate, or ovate; distance from beak tip to top of achene 0.8-2.2 mm.
                                               23 Perigynium body obovate, widest toward the tip (excluding the beak).
image of plant
Show caption*© Alex de la Paz
                                                 24 Perigynium beak spreading, slender; pistillate scales acute; styles sinuous at base
                                                 24 Perigynium beak appressed-ascending, triangular; pistillate scales obtuse; styles straight
                                               23 Perigynium body ovate, elliptic, or orbiculate, widest toward the base or near the middle (excluding the beak).
                                                    25 Inflorescences on tallest culms compact, 1.5-3 × as long as wide, erect, the spikes overlapping, the lowest internode of the inflorescence 1-6 (-7.5) mm, ½ to 1/5 (-¼) the length of the inflorescence
                                                      26 Achenes 0.6-0.9 mm wide; perigynia veinless or 1-3 veined on the inner face, these faint or basal only; inflorescences < 3.0 cm long
                                                      26 Achenes 0.9-1.3 mm wide; perigynia often 3-veined on the inner face; inflorescences 12-60 mm long.
                                                        27 Perigynia broadly elliptic or nearly orbiculate, the wing margin 0.4-0.8 mm wide, 0-6 veined on the inner face
                                                        27 Perigynia ovate to broadly ovate, the wing margin 0.25-0.45 mm wide, 4-7 veined on the inner face
                                                    25 Inflorescences on tallest culms elongate, more-or-less open toward the base, (2.5-) 3.0-5.1 × as long as wide, often arching or nodding at the tip; spikes more-or-less separate; lowermost internode (5-) 7-19 mm long, mostly 1/5-1/3 (-1/2) the length of the inflorescence.
                                                          28 Perigynium orbiculate, widest at mid-body
                                                          28 Perigynium narrowly to broadly ovate, widest below mid-body.
                                                            29 Sheaths smooth, often whitish-mottled; perigynium beak spreading, exceeding the pistillate scales by 0.7-1.6 mm; beak and shoulders of perigynia greenish to yellowish or greenish brown at maturity
                                                            29 Sheaths, at least some, papillose near the collar (at magnification of 30 ×), not prominently whitish-mottled; perigynium beak appressed or ascending in spikes, exceeding the pistillate scales by 0.0-0.8 mm; beak and shoulders of perigynia straw-colored to reddish-brown at maturity
                              15 Perigynia > 2 mm wide.
                                                              30 Spikes 12-28 mm long, with tapered base and acute tip; perigynium body lanceolate, 6-9 mm long; vegetative culms conspicuous
                                                              30 Spikes either shorter than 12 mm or longer and with either rounded bases or tips or both; perigynium body ovate, elliptic, orbicular, or obovate, or lanceolate (if lanceolate, then shorter than 6 mm long); vegetative culms conspicuous or not.
                                                                 31 Perigynium bodies obovate, widest toward the tip; leaf sheaths green-veined adaxially nearly to the summit, or with a narrow Y-shaped hyaline area.
                                                                   32 Achenes 1.3-1.8 mm wide
                                                                     33 Perigynia (5.6-) 6.0-7.1 × 3.3-4.6 (-4.8) mm, exceeding the subtending scale by 1.5-2.6 mm; staminate and proximal pistillate scales obtuse to acute; pistillate scales 2.4-3.2 (-3.4)× as long as wide
                                                                     33 Perigynia (4.5-) 4.8-6.0 (-6.3) × 2.5-3.8 mm, exceeding the subtending scale by (0.4-) 0.6-1.4 (-1.6) mm; staminate and proximal pistillate scales acuminate; pistillate scales (2.6-) 2.9-3.7 (-4.2)× as long as wide
                                                                   32 Achenes 0.75-1.2 (-1.3) mm wide.
                                                                       34 Inflorescences arching or nodding, 2.3-8.4 cm long; spikes widely separated.
                                                                         35 Sheaths smooth, summits concave, only reaching base of leaf blade; pistillate scales yellowish to reddish brown; [Interior Highlands and adjacent provinces, AR, LA, OK, and ne. TX]
                                                                         35 Sheaths finely papillose (use at least 30× magnification), summits truncate, prolonged 1-4 mm beyond collar; pistillate scales white-hyaline; [coastal, south to e. VA]
                                                                       34 Inflorescences erect, 1-4.5 cm long; spikes slightly separated to congested.
image of plant
Show caption*© Alex de la Paz
                                                                           36 Perigynium beak spreading, slender; pistillate scales acute; styles sinuous at base
                                                                           36 Perigynium beak appressed-ascending, triangular; pistillate scales obtuse; styles straight.
                                                                              37 Perigynia veinless on adaxial face; leaves 3-6 (-8) mm at widest; sheaths truncate at summit and extending 0.3 mm beyond collar
                                                                              37 Perigynia veined on adaxial face; leaves 2-4 (-4.5) mm at widest; sheaths concave at summit and not prolonged beyond collar.
                                                                                38 Pistillate scales white-hyaline to pale silvery-brown, obtuse; achenes 0.7-1 mm wide; achene apiculum < 0.4 mm long; [widespread]
                                                                                38 Pistillate scales reddish brown, acute; achenes 0.9-1.2 mm wide; achene apiculum 0.4-0.8 mm long; [Interior Highlands and adjacent areas]
                                                                 31 Perigynium bodies lanceolate, ovate, elliptic, orbicular, or reniform, widest at the middle or toward the base; leaf sheaths various, some with prominent hyaline band near the apex adaxially.
                                                                                  39 Plants colonial, from creeping rhizomes; vegetative culms numerous, conspicuous, strongly 3-ranked, with 15-35 leaves when fully-developed; achenes 1.6-2 × as long as wide; larger spikes with 5-25 (-30) perigynia
                                                                                  39 Plants clumping; vegetative culms few, inconspicuous, usually with fewer than 15 leaves, not strikingly 3-ranked; achenes 1-1.6 (-1.7) × as long as wide; larger spikes with 15-80 perigynia.
                                                                                    40 Perigynia finely granular-papillose (as seen with 30× magnification), the body reniform to orbiculate, 0.6-0.9 ×as long as wide, 3.5-4.5 (-4.9) mm wide; lowermost pistillate scale obtuse-rounded
                                                                                    40 Perigynia smooth, the body broadly ovate, elliptic, orbicular, or slightly obovate, (0.7-) 0.9-1.7 × as long as wide, 1.5-6.1 mm wide; lowermost pistillate scales obtuse to acuminate-awned.
                                                                                      41 Perigynia 5.5-8.0 (-8.7) × (3.1-) 3.3-6.3 mm at largest (except sometimes in C. bicknellii and C. shinnersii), often prominently bulged on both faces; beak (1.4-) 1.6-2.5 (-3.4) mm long.
                                                                                        42 Perigynia 3.5-6.3 mm at widest, veinless over achenes adaxially or nearly so; at least proximal staminate scales, especially of terminal spike and sometimes proximal pistillate scales, with midvein excurrent as scabrous awn 0.1-0.9(-2.4) mm; larger culms with 2-4(-5) spikes
                                                                                        42 Perigynia (2.5-) 2.7-4.8 mm at widest, (0-) 1-8-veined over achene adaxially; staminate and pistillate scales obtuse to acuminate-awned, midvein not excurrent as scabrous awn; larger culms with (3-) 4-7 (-11) spikes.
                                                                                           43 Leaf sheaths finely papillose, at least near apex; perigynia membranaceous, with brown achene clearly visible through hyaline adaxial face, usually with reddish brown tinged wings, strongly, evenly 4-8-veined adaxially over achene; pistillate scales usually reddish brown; anthers (2.4-)2.8-4.2 mm; plants in small clumps (usually fewer than 25 culms) in dry to mesic habitats
                                                                                           43 Leaf sheaths smooth; perigynia herbaceous, opaque, with achene not clearly visible through adaxial face, with greenish or pale brown wings, finely and irregularly (0-)1-7-veined over achene adaxially; pistillate scales pale yellowish brown to brown; anthers (1.8-)2.2-3.6 mm; plants often in dense, large clumps (to 200 culms) in wet habitats.
                                                                                             44 Staminate and pistillate scales acuminate-awned, tip white to brownish hyaline, membranaceous, often ± curled, midvein fading before tip; beak of larger perigynia 2.0-2.6 (-2.8) mm long; perigynium body (1.3-) 1.4-2.1× as long as the beak
                                                                                             44 Staminate and pistillate scales obtuse to acuminate, tip firm, herbaceous, flat or inrolled, midvein prominent to tip; beak (1.2-) 1.5-2.1 (-2.3) mm long; perigynium body 1.9-3× as long as the beak
                                                                                      41 Perigynia 2.5-5.5 × 2.0-3.6 mm at largest (to 6.1 × 4.4 mm in the Florida endemic C. vexans), prominently bulged by achene only on abaxial face or flat; beak usually 0.7-1.6 (-1.8) mm long.
                                                                                               45 Leaf sheaths green-veined adaxially nearly to the summit; inflorescences dense to somewhat open, erect, the lowermost internode usually < 8 (-12) mm long
                                                                                                 46 Perigynia with acute bases, 2.0-2.8 mm wide; beak appressed, > 2/5 × the length of the body; broadest leaves 1.5-2.5 mm wide; [of sw. VA northward]
                                                                                                 46 Perigynia with rounded bases, 3.0-4.4 mm wide; beak spreading, ca. ⅓ × the length of the body; broadest leaves 2-5 mm wide; [of FL]
                                                                                               45 Leaf sheaths with white-hyaline area adaxially; inflorescences open or dense.
                                                                                                   47 Perigynium body narrowly to broadly ovate, greenish; pistillate scales with green midstripe, hyaline or pale margins (rarely brown tinged); leaves 2.5-6.5 mm wide, the sheaths green mottled, with mouth truncate, and prolonged to 2 mm distal to base of the leaf blades
                                                                                                   47 Perigynium body broadly ovate, broadly elliptic, or orbiculate, yellowish to tan brown; pistillate scales greenish or dark brown; leaves 1.5-4 (-5) mm wide, the sheaths usually evenly colored, with mouth concave.
                                                                                                     48 Leaf sheaths finely papillose (at magnification of 30-40 ×), especially near the leaf base.
                                                                                                        49 Perigynia strongly and evenly 4-8-veined over the achene adaxially, (4.5-) 5.1-5.5 mm long; pistillate scales usually (1.0-) 1.4-2.3 mm shorter than the perigynia; anthers (2.4-) 2.8-4.2 mm long
                                                                                                        49 Perigynia veinless or faintly and irregularly 0-4 (-6)-veined over the achene adaxially, 2.5-4.2 mm long; pistillate scales 0.2-1.3 mm shorter than the perigynia; anthers 1.0-2.1 mm long
                                                                                                          50 Perigynia 2.3-3.5 mm wide; distance from summit of achene to tip of beak 1.8-3.1 mm; achenes 1.1-1.5 mm wide; spike apex rounded or nearly acute; [Long Island west to n. OH and s. WI, northward]
                                                                                                          50 Perigynia 1.5-2.3(-2.5) mm wide; distance from summit of achene to tip of beak 0.8-1.7(-2) mm; achenes 1-1.3 mm wide; spike apex rounded; [widespread throughout eastern and midwestern US]
                                                                                                     48 Leaf sheaths smooth.
                                                                                                            51 Spikes on larger culms (3-) 5-7 (-11), tapered at the base, the terminal spike with a conspicuous staminate base; inflorescences typically open, 2.5-4.5 (-6.5) cm long, the lowermost internode (3-) 4-13 (-23) mm long; perigynium body (0.7-) 0.9-1.3 × as long as wide.
                                                                                                              52 Achenes 1.2-1.8 mm long, 1.0-1.3 mm wide; perigynia 2.5-4.2 mm long, 1.5-2.3 (-2.5) mm wide, mostly 2-4 (-6)-veined adaxially
                                                                                                              52 Achenes (1.6-) 1.7-2.2 mm long, (1.2-) 1.4-1.8 mm wide; perigynia 3.2-5.5 mm long, 2.5-3.6 mm wide, veinless or faintly 1-5 (-7)-veined adaxially.
                                                                                                                53 Perigynia 3.2-4.8 (-5.2) mm long; beak 0.8-1.5 mm long; pistillate scales 3.3-4.0 (-4.3) mm long, acute; achenes 1.0-1.3 (1.4) × as long as wide
                                                                                                                53 Perigynia (5.6-) 6.0-7.1 mm long; beak (1.2-) 1.5-2.1 (-2.3) mm long; pistillate scales (3.6-) 3.9-5.0 mm long, obtuse to acute
                                                                                                            51 Spikes on larger culms 2-4 (-5), rounded at the base, the terminal spike usually lacking a conspicuous staminate base; inflorescences compact, 1.2-3.0 (-3.6) cm long, the lowermost internode 1.5-7 (-13) mm long; perigynium body (0.7-) 0.9-1.6 × as long as wide.
                                                                                                                  54 Achenes of larger perigynia ellipsoid to narrowly oblong, 0.9-1.3 mm wide, 1.3-1.6 × as long as wide; perigynia (25-) 30-80 per spike, squarrose-spreading at maturity, 1.8-3.0 mm wide
                                                                                                                  54 Achenes of larger perigynia broadly oblong to nearly orbicular, 1.35-1.8 mm wide, 1-1.3 × as long as wide; perigynia (10-) 15-40 (-45) per spike, appressed-ascending at maturity, (2.1-) 2.5-3.4 (-3.5) mm wide.
                                                                                                                     55 Perigynia veinless or faintly and irregularly 1-5-veined over the achene adaxially, more-or-less orbicular, the bodies (2-) 2.3-3.2 mm long, (0.7-) 0.9-1.1 (-1.3) × as long as wide; pistillate scales mostly acute, about as long as to 0.7 (-0.9) mm shorter than the subtended perigynium (flattened and measured separately)
                                                                                                                     55 Perigynia strongly 4-6-veined over the achene adaxially, broadly ovate to broadly elliptic, (or rarely nearly orbicular), the bodies (2.7-) 3-4 mm long, (0.9-) 1.0-1.6 × as long as wide; pistillate scales mostly obtuse, 0.7-1.7 mm shorter than the subtended perigynium (flattened and measured separately)

Key to Carex, [26qq] Section 30 Vesicariae: section Vesicariae [including 52 - Pseudocypereae]

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1 Pistillate scales with a prominent, scabrous awn (the body of the scale often ciliate as well).
  2 Plants extensively colonial from elongate, creeping rhizomes; staminate scales acute to acuminate, essentially smooth-margined except at the very tip; perigynia 7-11-nerved
  2 Plants densely to loosely cespitose, the rhizomes connecting individual culms in a clump < 10 cm long; staminate scales (at least some of them) with a distinct, scabrous awn; perigynia 6-25-nerved.
    3 Perigynia 6-12-nerved, the nerves separate nearly to the beak apex; perigynium bodies broadly ellipsoid to more or less globose, (1.8-) 2.0-4.2 mm wide; achenes rough-papillate.
      4 Spikes 9-14 (-15) mm thick; widest leaves 2.4-4.0 (-5) mm wide; spikes usually 2.5-3.5× as long as wide; perigynia 4.8-6.6 (-7.6) mm long, the beaks usually 0.7-1.3× as long as the body
      4 Spikes (12-) 15-22 mm thick; widest leaves (4.0-) 4.5-13 mm wide; spikes usually < 2.5× as long as wide if < 15 mm thick; perigynia (6-) 6.5 (-10.8) mm long, the beaks 0.6-0.9× as long as the body
    3 Perigynia 12-25-nerved, the nerves (except for 2 prominent laterals) confluent at or below the middle of the beak; perigynium bodies ellipsoid to lance-ovoid, 1.1-2.2 mm wide; achenes smooth.
        5 Perigynia spreading to ascending, herbaceous, ± inflated, terete to somewhat flattened, many veins separated by more than 3× their width; longest beak teeth 0.3-0.9 mm long
        5 Perigynia ± reflexed when mature, leathery, uninflated, compressed-triangular, strongly and closely veined with most veins separated by less than 2× their width; longest beak teeth 0.7-2.1 (-2.8) mm long.
          6 Spikes 12-18 mm thick; beak teeth strongly out-curved, longest 1.3-2.1 (-2.8) mm long
          6 Spikes 9-12 mm thick; beak teeth straight or slightly out-curved, longest teeth 0.7-1.2 (-1.4) mm long
1 Pistillate scales smooth-margined, obtuse to acuminate, awnless (rarely the lowermost scales awned in C. utriculata).
             7 Leaves filiform-involute, wiry, (0.5-) 1-3 (-3.2) mm wide; stems smooth, round or obtusely trigonous in cross-section; [rare, in cool temperate peatlands northward and limited to high elevation mountain bogs southward]
             7 Leaves flat, U-, V-, or W-shaped in cross-section, the widest 1.5-12 (-15) mm wide; stems often scabrous-angled, round to trigonous; [collectively widespread].
               8 Achenes asymmetrical, deeply indented or invaginated on one face; widest perigynia (4.0-) 4.5-7 mm wide; beaks 2.4-4.8 mm long, smooth
               8 Achenes symmetrical; widest perigynia (2-) 2.5-3.5 (-4.5) mm wide; beaks 1-4.2 (-4.8) mm long, scabrous or smooth.
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Show caption*© Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman
                 9 Perigynium beaks finely scabrous (at least near the tip and on the teeth), 2.4-4.2 (-4.8) mm long; widest leaves 1.8-4.3 (-5) mm wide.
                   10 Pistillate spikes mostly >2× longer than wide, cylindrical in outline; [s. Appalachians and ne US]
                   10 Pistillate spikes mostly <1.5× longer than wide, globose in outline; [widespread]
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Show caption*© Scott Ward
                 9 Perigynium beaks smooth, 1-4.5 mm long; widest leaves 1.5-15 mm wide.
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Show caption*© Keith Bradley
                     11 Pistillate spikes globose or short ovoid, ca. 3-20-flowered; [plants of the Coastal Plain from e. NC southward]
                     11 Pistillate spikes cylindric, ca. 20-150-flowered; [plants collectively of the Mountains, from nw. NC northward].
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Show caption*© Mark Kluge, some rights reserved (CC BY-NC), uploaded by Mark Kluge
                       12 Bract of lowest pistillate spike (excepting isolated spikes from long-sheathing bracts on the lower part of the stem) (2.5-) 3-9× as long as the inflorescence; staminate spike often 1, slightly (if at all) elevated above the summit of the crowded pistillate spikes; perigynia reflexed
                       12 Bract of lowest pistillate spike (excepting isolated spikes from long-sheathing bracts on the lower part of the stem) 0.5-2.5× as long as the inflorescence; staminate spikes 2-4 (-5), well elevated above the summit of the crowded pistillate spikes; perigynia spreading or ascending.
                          13 Plant colonial from long-creeping rhizomes; widest leaves (4.5-) 5-12 (-15) mm wide; ligules about as long as wide; basal sheaths usually spongy-thickened and only slightly or not red-tinged
                          13 Plant cespitose; widest leaves 1.8-6.5 mm wide; ligules longer than wide; basal sheaths not spongy-thickened and often tinged with reddish-purple

Key to Carex, [26r] Section 13 Phacocystis: section Phacocystis (Cryptocarpae and Acutae)

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1 Lowest spike erect or ascending.
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Show caption*© Nate Hartley, some rights reserved (CC BY-NC), uploaded by Nate Hartley
  2 Lower sheaths scabrous, reddish-brown, the sheath fronts (ventral faces) with prominent veins forming a persistent network; lower sheaths usually bladeless
  2 Lower sheaths glabrous, the sheath fronts (ventral faces) not forming a persistent network; lower sheaths usually with leaf blades.
    3 Perigynia evidently nerved on both faces
      4 Pistillate scales with apex acute, acuminate, or mucronate
      4 Pistillate scales (at least the lowermost) with a prominent, scabrous awn
    3 Perigynia not nerved, or very faintly nerved.
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Show caption*© Alex Graeff, some rights reserved (CC BY-NC-ND), uploaded by Alex Graeff
        5 Longest bracts overtopping the spikes; perigynia flattened, elliptic to obovate; pistillate scales acute to obtuse, generally shorter than the perigynia
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        5 Longest bracts shorter than the spikes; perigynia inflated, obovate; pistillate scales acuminate, longer than the perigynia
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1 Lowest spike pendent.
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          6 Pistillate scales awnless, the sides black or deep purple-brown; perigynia usually divergent, with apices often slightly reflexed at maturity
          6 Pistillate scales awned, the sides dark reddish-brown, light golden-brown, tan, or clear; perigynia divergent or ascendent, the apices straight or slightly reflexed at maturity.
             7 Sheath backs glabrous [prickles 0-1 (-5) per mm2 of sheath surface 5 cm from base]; perigynia somewhat inflated, obovoid, rounded above to an abrupt beak; lowest bract of the infructescence 17-62 cm long.
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               8 Perigynia strongly obovoid, 3-4.5 mm long, 2-3 mm wide; achene symmetrical
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Show caption*© Nate Hartley, some rights reserved (CC BY-NC), uploaded by Nate Hartley
               8 Perigynia ellipsoid to slightly obovoid, 2-3 (-3.5) mm long, 1-2 mm wide; achene usually shortened on one side, slightly to strongly asymmetrical
             7 Sheath backs scabrous [prickles (1-) 5-54 per mm2 of sheath surface 5 cm from base]; perigynia flattened, elliptic to ovoid, tapering from near or below the middle to a minute beak; lowest bract of the infructescence 7-35 cm long.
                 9 Perigynia densely granular-papillose throughout, the papillae mostly > 13 μm long; lower pistillate scales usually truncate or retuse, abruptly awned; sheaths finely scabrous; achenes not constricted when at maturity; [more commonly in the piedmont and coastal plain but also scattered inland]
                 9 Perigynia smooth to slightly papillose toward the apex, the papillae mostly < 10 μm long; lower pistillate scales usually acute or acuminate, tapering into the awn; sheaths strongly scabrous; [primarily montane in distribution southward (C. fumosimontana), or montane southward and more commonly in a variety of wetlands northward (C. gynandra)].
                   10 Pistillate and staminate scale bodies dark reddish-brown; apex of pistillate scale bodies retuse with rounded shoulders, the awn extending from the notch; sheath faces with reddish-brown prickles; widest leaves per plant (3-) 4.5-6.5 (-8) mm wide; longest proximal spikes (29-) 42-60 (-76) mm long; longest distal spikes (20-) 29-40 (-48) mm long
                   10 Pistillate and staminate scale bodies clear, tan, or light golden-brown; apex of pistillate scale bodies acuminate to rounded (or rarely obliquely truncate) into the awn base; sheath faces with colorless prickles; widest leaves per plant (5-) 6.5-10.5 (-14) mm wide; longest proximal spikes (35-) 51-93 (-125) mm long; longest distal spikes (20-) 33-58 (-82) mm long

Key to Carex, [26rr] Section 31 Lupulinae: section Lupulinae

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1 Sheath of uppermost leaf absent or <1.5 (-2.5) cm long; beak of perigynia 1.5-4.2 mm long; achenes with elliptic or obovate sides.
  2 Perigynia rhombic-ovoid, cuneate to the base, 8-35 per spike, radiating in all directions and therefore forming a globular spike
  2 Perigynia lanceoloid to ovoid, convex to the base, 1-12 (-20) per spike, ascending to spreading (the lowest sometimes slightly reflexed) and therefore forming an ovoid to obovoid spike.
    3 Perigynia 3-5 mm wide at the widest point; achenes broadest above the middle, with a pronounced shoulder rounding abruptly to the tip; style of mature achene with a half to full coil in its lower portion; [of high elevations in our area, generally in spruce-fir or northern hardwoods forests]
    3 Perigynia 5-8 mm wide at the widest point; achenes broadest at the middle, smoothly rounded to the tip; style of mature achene straight or arcuate; [widespread in our area]
1 Sheath of uppermost leaf usually >1.7 cm long; beak of perigynia 4.5-10 mm long; achenes with rhombic or nearly triangular sides.
      4 Achenes distinctly wider than long, widest above the middle; perigynia stiffly spreading at right angles to the rachis
      4 Achenes as wide as long or longer, widest near the middle; perigynia ascending.
        5 Angles of the achenes pointed, often even knobbed, with nipple-like points; achenes (2.2-) 2.4-3.4 mm wide, often nearly as wide as long
        5 Angles of the achenes smoothly curved, not pointed or knobbed; achenes 1.7-2.6 (-2.8) mm wide, distinctly longer than wide.
          6 Staminate peduncle (3-) 6-18 cm long, usually exceeding the uppermost spike by 2-12 cm; plants loosely colonial by long slender rhizomes
          6 Staminate peduncle 0.5-6 (-7) cm long, shorter than to exceeding the uppermost pistillate spike by < 2 cm; plants solitary or loosely cespitose in small clumps connected by stout, short rhizomes

Key to Carex, [26s] Section 14 Racemosae: section Racemosae (Atratae)

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1 One species
1 One species

Key to Carex, [26ss] Section 32 Rostrales: section Rostrales (Folliculatae)

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1 Perigynia 6.4-10.7 mm long, 2.6-3.9× as long as wide
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1 Perigynia (8.3-) 10.5-15.6 mm long, 4-7× as long as wide.
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Show caption*© David McCorquodale, some rights reserved (CC BY), uploaded by David McCorquodale
  2 Widest leaf blades 1.6-3.5 (-4.2) mm wide; bract sheaths concave at the apex; [of MD northward]
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Show caption*© Gary P. Fleming
  2 Widest leaf blades (3.5-) 5-18 mm wide; bract sheaths truncate to convex at the apex; [collectively widespread in our area].
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Show caption*© Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman
    3 Pistillate scales usually awned (rarely merely cuspidate); pistillate scales (including the awn, if present) 0.5-1.2× as long as the perigynia; larger achenes 3.4-4.0 (-4.5) mm long (ca. (1.7-2.4x as long as wide); widest leaves of vegetative shoots 8-18 (-21) mm wide; pistillate spikes normally not staminate at apex (rarely with a few staminate flowers); [primarily of the Mountains and Piedmont]
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    3 Pistillate scales acute or long-acuminate (rarely short-awned); pistillate scales (including the awn, if present) 0.3-0.6× as long as the perigynia; larger achenes 2.3-3.4 (-3.8) mm long (ca. 1.3-1.8x as long as wide); larger leaves mostly 4-12 mm wide; pistillate spikes normally staminate at apex; [primarily of the Coastal Plain]

Key to Carex, [26tt] Section 33 Collinsiae: section Collinsiae

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1 One species
1 One species

Key to Carex, [26u] Section 15 Limosae: section Limosae (including Scitae)

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1 Pistillate scales 2.0-3.8 mm wide, wider than the perigynia
1 Pistillate scales 1.2-2.0 mm wide, narrower than the perigynia.
  2 Proximal bracts shorter than inflorescences; terminal spikes 20-50 mm long; pistillate scales shorter than perigynia
  2 Proximal bracts equaling or exceeding inflorescences; terminal spikes 7-20 mm long; pistillate scales exceeding perigynia

Key to Carex, [26uu] Section 34 Squarrosae: section Squarrosae

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1 Terminal spike usually entirely staminate; pistillate scales with an awn equaling or surpassing the perigynium; achenes 1.2-2.1 mm long.
  2 Pistillate scales 0.4-0.9 (-1.1) mm wide, the body wide and translucent; staminate scales 0.9-1.6 mm wide, tightly imbricate in the spike; plants colonial, long-rhizomatous
  2 Pistillate scales 0.1-0.4 mm wide, the body narrow and indistinct; staminate scales 0.3-0.8 mm wide, irregularly imbricate with spreading tips; plant cespitose, short-rhizomatous
1 Terminal spike gynecandrous, mainly pistillate; pistillate scales awnless, or with a short awn not surpassing the perigynium; achenes 2.0-3.0 mm long.
    3 Achene 1.9-2.5× as long as wide; style persistent, strongly kinked at the base; spikes 1-2 (-3) per stem
    3 Achene 1.2-1.9× as long as wide; style deciduous, straight or slightly curved; spikes (1-) 2-4 (-6) per stem

Key to Carex, [26v] Section 15.5 Thuringiaca: section Thuringiaca

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1 One species [exotic, rare escape from cultivation]
1 One species [exotic, rare escape from cultivation]

Key to Carex, [26vv] Section 35 Shortianae: section Shortianae

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1 One species
1 One species

Key to Carex, [26w] Section 16 Rhynchocystis: section Rhynchocystis

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1 One species; [exotic, rare escape from cultivation]
1 One species; [exotic, rare escape from cultivation]

Key to Carex, [26ww] Section 36 Spirostachyae: section Spirostachyae (Extensae)

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1 Leaves of flowering stems flat, the widest 3.3-5.0 mm wide
1 Leaves of flowering stems channeled or involute, the widest 1.0-3.5 (-4.3) mm wide

Key to Carex, [26x] Section 17a Glaucescentes: section Glaucescentes (Pendulinae)

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1 Awn of the pistillate scale tapering gradually into the scale; perigynium 2-ribbed, and also distinctly and evenly nerved between the ribs; [of swamps and marshes]
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1 Awn of the pistillate scale emerging from a retuse notch in the apex of the scale; perigynium 2-ribbed, obscurely nerved between the ribs; [generally of acid seepages, pocosins, and blackwater situations, often associated with Pinus serotina].
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  2 Lowest pistillate spike drooping, on a peduncle 1-4 cm long; perigynia reddish-glaucous, lacking nerves; achenes slightly longer than wide
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  2 Lowest pistillate spike erect, sessile or with a peduncle up to 1 cm long; perigynia white-glaucous, rather distinctly 6-8 nerved; achenes as wide as long

Key to Carex, [26xx] Section 37 Ceratocystis: section Ceratocystis

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1 Pistillate scales coppery brown; terminal (staminate) spike 6-24 mm long; culms 0.2-8 dm tall.
  2 Perigynia 4.0-6.3 mm long; pistillate spikes 7.5-12.9 mm wide (measured beak tip to beak tip); perigynium beaks 1.6-2.5 mm long, comprising 40-50% of the total length of the perigynium
  2 Perigynia 1.8-3.0 (-3.9) mm long; pistillate spikes 3-8 mm wide (measured beak tip to beak tip); perigynium beaks 0.5-1.0 mm long, comprising 20-30% of the total length of the perigynium.
    3 Proximal pistillate spike remote, often nearly basal; perigynia and foliage often olive or dark green; culms often arcuate or sinuous; staminate spikes on peduncles 3-28 mm
    3 Pistillate spikes contiguous or aggregated; foliage grayish or light green; perigynia grayish green to yellowish green; culms erect; staminate spikes on peduncles to 20 mm
1 Pistillate scales yellowish green; terminal (staminate) spike 12-39 mm long; culms 1-12.5 dm tall.
      4 Larger pistillate spikes 10.5-13.5 (14.0) mm wide (measured beak tip to beak tip); longer perigynium beaks 2.3-3.2 mm long; [MI south to extreme s. OH and c. IN]
      4 Larger pistillate spikes 7-11 mm wide; longer perigynium beaks 1.2-2.3 mm long; [either of calcareous savannas of the Coastal Plain of NC or of acid situations in NJ, n. OH, n. IN, and northward].
        5 Terminal (staminate) spike 12-21 mm long; pistillate spikes (1-) 2-5 per culm; tallest culms of a plant 2.5-5 dm tall; achenes 1.0-1.2 mm wide; [of acid situations in NJ, n. OH, n. IN, and northward]
        5 Terminal (staminate) spike (9-) 17-39 mm long; pistillate spikes 1-2 (-3) per culm; tallest culms of a plant 6.5-12.5 dm tall; achenes 1.2-1.5 mm wide; [of calcareous savannas of the Coastal Plain of NC]

Key to Carex, [26z] Section 17b Bicolores: section Bicolores

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1 Perigynia orange-colored when ripe, smooth to minutely papillose; lateral spikes lax; terminal spikes usually staminate, 0.9-2 mm wide; both perigynia and pistillate scales divergent when mature
1 Perigynia whitish-green colored when ripe, densely papillose; lateral spikes dense; terminal spikes usually gynecandrous, 0.2-0.7 mm wide; both perigynia and pistillate scales ascending when mature

Key to Carex, Key A: Subkey in Carex

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1 Leaf blades 20-60 mm wide, without a midrib (with 40-100 parallel nerves all of equal prominence), leathery, the apex obtuse; leaf margin scarious, minutely crisped-ruffled (feeling scaberulous to the touch)
1 Leaf blades 0.5-25 (-52) mm wide, with a midrib, herbaceous, the apex acute; leaf margin various (smooth or scabrous, but not as described below).
  2 Spike entirely staminate.
    3 Culms distinctly red or purple at the base
    3 Culms yellow to brown or black, without red or purple coloration.
      4 Culms shorter than the leaves; widest leaf blades > 2 mm wide
      4 Culms longer than the leaves; widest leaf blades < 2 mm wide
  2 Spike pistillate or with both pistillate and staminate flowers.
        5 Stigmas 2; achenes lenticular.
          6 Perigynia very obscurely or not at all serrulate, plump; plants slender rhizomatous
          6 Perigynia minutely but strongly and regularly serrulate on apical portion and beak, ± flattened; plants cespitose
        5 Stigmas 3; achenes trigonous.
             7 Perigynia pubescent near the tip
             7 Perigynia glabrous.
               8 Spikes gynecandrous; beak of perigynium with apical teeth > 0.3 mm long
               8 Spikes androgynous or entirely pistillate; beak of perigynium with apex entire, emarginate, or with teeth < 0.2 mm long.
                 9 Lower pistillate scales > 10 mm long
                 9 Lower pistillate scales < 10 mm long.
                   10 Perigynium beak > 2 mm long, as long as or longer than the perigynium body
                   10 Perigynium beak < 2 mm long, or if more, then tapering to the perigynium body and shorter than the body.
                     11 Perigynia > 4× as long as wide
                     11 Perigynia < 4× as long as wide.
                       12 Perigynia 1-3, each with 2 marginal veins only
                       12 Perigynia 2-13, each lightly many-veined on the body in addition to 2 marginal veins

Key to Carex, Key B: Subkey in Carex

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1 Widest leaves 4-8 mm wide; inflorescences more-or-less capitate (occasionally with the lowermost 1 or 2 spikes separated
1 Widest leaves 1-4 mm wide; inflorescences ovoid to cylindric

Key to Carex, Key C: Subkey in Carex

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1 Perigynia surfaces and beak often pubescent, finely papillate
1 Perigynia glabrous, papillate or not.
  2 Lateral spikes usually pedunculate; lowermost inflorescence bracts sometimes with sheath; peduncles with prophyll at base.
    3 Terminal spike gynecandrous, pistillate flowers as many as or more numerous than staminate; lateral spikes short, not much longer than wide; fresh perigynia white-pulverulent
    3 Terminal spike usually staminate or, sometimes, gynecandrous, staminate flowers then more numerous than pistillate; lateral spikes oblong, distinctly longer than wide; fresh perigynia green or slightly glaucous.
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      4 Pistillate scales (at least the lower) long-awned
      4 Pistillate scales obtuse to acuminate or cuspidate.
        5 Perigynia smooth; style persistent on the achene
        5 Perigynia often papillose over most of the surface; style deciduous
  2 Lateral spikes sessile; bracts sheathless; peduncles without (or rarely with) a prophyll
          6 Perigynia papillose (visible at 20× magnification).
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             7 Terminal spike staminate, androgynous, or gynecandrous (if gynecandrous, the staminate flowers more numerous than the pistillate); lateral spikes at least 2× as long as wide
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             7 Terminal spike staminate or gynecandrous (if gynecandrous, the pistillate flowers more numerous than the staminate); lateral spikes not much longer than wide
          6 Perigynia smooth.
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               8 Terminal spike gynecandrous; lateral spikes gynecandrous or pistillate.
                       12 Margins of perigynia flat, at least in the upper ½, flat portion (measured at the tip of the achene and base of beak) > (0.1-) 0.2 mm wider
                          13 Achenes rounded at apex (style dehiscing at the surface of the achene); style conspicuously enlarged at the base
                          13 Achenes with short apiculus formed by the persistent base of the style; style not conspicuously enlarged at base
                       12 Margins of perigynia rounded, or with flat portion < 0.1 mm wide.
                            14 Margins of perigynia rounded or with a very narrow rounded edge; achenes nearly filling the perigynium bodies
                            14 Margins of perigynia sharply edged or narrowly winged; achenes distinctly smaller than the perigynium bodies.
                              15 Inflorescences in fruit 1-1.5× as long as wide
                              15 Inflorescences in fruit 1.5-2 (or more)× as long as wide.
                                16 Lowermost perigynia in each spike spreading
                                16 Lowermost perigynia in each spike ascending or erect.
                                  17 Perigynium serrulate on the margins of the upper body and lower beak
                                  17 Perigynium entire on the margins of the upper body and the lower beak
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               8 Terminal spike androgynous (rarely entirely staminate or entirely pistillate); lateral spikes androgynous, staminate, or pistillate.
                 9 Sheath fronts of lower cauline leaves transversely rugose.
                   10 Perigynia mostly > 2× as long as wide, widest near the base
                   10 Perigynia mostly < 2× as long as wide, widest near middle.
                     11 Inflorescence usually branched, at least at the base, usually with > 15 spikes; pistillate scales usually yellow or brown, sometimes with hyaline margins, 3-veined
                     11 Inflorescence unbranched or with 1 or 2 short branches at the base, with < 15 spikes; pistillate scales greenish hyaline, 1-veined
                 9 Sheath fronts of lower cauline leaves smooth (or very weakly and indistinctly transversely rugose).
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Show caption*© Erik Danielson
                                    18 Fronts of leaf sheaths dotted red, brown, or yellow.
                                       19 Perigynia widest near the base; culms usually > 1 mm wide
                                       19 Perigynia widest near the middle; culms usually < 1 mm wide.
                                         20 Plants densely cespitose, with short rhizomes; pistillate scales acute to acuminate
                                         20 Plants loosely cespitose, sometimes with long rhizomes; pistillate scales (at least the upper) obtuse
                                    18 Fronts of leaf sheaths not dotted red, brown, or yellow.
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Show caption*© Matt Berger, some rights reserved (CC BY), uploaded by Matt Berger
                                           21 Perigynium beak < 0.25 mm long, the margins entire
                                           21 Perigynium beak > 0.25 mm long, the margins often serrulate.
                                             22 Upper leaves of culms with front of sheaths green-veined, not differentiated from the rest of the sheath
                                             22 Upper leaves of culms with front of sheaths with at least a narrow hyaline or whitish-hyaline band extending at least ½ the length of the sheath.
                                               23 Perigynia with flat, winglike margins > 0.1 mm wide; plants long-rhizomatous, not cespitose, sometimes forming large colonies
                                               23 Perigynia without a flat margin, or with a flat margin < 0.1 mm wide; plants short-rhizomatous or inconspicuously rhizomatous, cespitose or not, sometimes forming large colonies.
                                                 24 Plants colonial from long rhizomes or stoloniferous (proliferating from last year’s decumbent sterile culms)
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                                                    25 Plants long stoloniferous, proliferating from last year’s decumbent sterile culms
                                                    25 Plants rhizomatous from creeping rhizomes 1.8-3.5 mm in diameter
                                                 24 Plants cespitose.
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                                                      26 Spikes not consistently androgynous, the terminal either entirely staminate or pistillate, the lateral spikes irregularly pistillate, or staminate, or mixed
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                                                      26 Spikes consistently androgynous, occasionally some of the lateral spikes entirely pistillate.
                                                        27 Perigynium widest near the base, tapering from base to beak
                                                        27 Perigynium widest above the base, often abruptly beaked

Key to Carex, Key D: Subkey in Carex

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1 Pistillate spikes all from the base of the plant
1 Pistillate spikes all or in part borne on the elongate, aboveground stem.
  2 Bracts of the lowermost non-basal spike with well-developed sheath > 4 mm long.
    3 Beak of perigynium with distinct teeth > 0.6 mm long
    3 Beak of perigynium entire, notched, or with indistinct teeth < 0.6 mm long.
      4 Bracts of the lowermost non-basal spike bladeless, or with a blade < 2 mm long.
        5 Perigynia 2.0-2.9 mm long; leaf blades 0.9-3.3 mm wide
        5 Perigynia 4-5 mm long; leaf blades 4-8 mm wide
      4 Bracts of the lowermost non-basal spike with blade > 3 mm long (and often much longer).
          6 Achene tip with persistent, enlarged, circular style base
          6 Achene tip with at most a short apiculus.
             7 Leaves pubescent or pilose
             7 Leaves usually glabrous, to scabrous on the veins.
               8 Bases of plants brown
               8 Bases of plants distinctly red or purple.
                 9 Lowermost pistillate scales awned; leaves somewhat septate-nodulose; plants usually long-rhizomatous and forming large clonal colonies
                 9 Lowermost pistillate scales obtuse to acuminate; leaves not septate-nodulose; plants cespitose, short-rhizomatous
  2 Bracts of the lowermost non-basal spike sheathless or with sheath < 4 mm long.
                   10 Perigynia > 10 mm long.
                     11 Pistillate spikes globose, about as long as wide; staminate spikes usually 1
                     11 Pistillate spikes cylindric, much longer than wide; staminate spikes 1-8
                   10 Perigynia < 10 mm long.
                       12 Perigynium beak with 2 teeth > 0.6 mm long
                       12 Perigynium beak entire or with teeth < 0.6 mm long.
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                          13 Terminal spike gynecandrous or pistillate
                            14 Perigynia papillate
                            14 Perigynia glabrous or pubescent.
                              15 Sheaths and blades both glabrous
                              15 Sheaths and/or blades pubescent
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                          13 Terminal spike staminate (or rarely androgynous).
                                16 Leaf sheaths (and usually the blades as well) pubescent.
                                  17 Pistillate scales sometimes pubescent; pistillate spikes with 40-200 perigynia
                                  17 Pistillate scales glabrous; pistillate spikes with < 40 (-50) perigynia.
                                    18 Perigynia usually < 3.2 mm long, the apex rounded and beakless, or abruptly beaked
                                    18 Perigynia > 3.5 mm long, the tip tapering or abruptly beaked.
                                       19 Longer peduncles of pistillate spikes > 1 cm long; perigynia > 3× as long as wide, tapering gradually to the base
                                       19 Longer peduncles of pistillate spikes 0-1 cm long; perigynia < 3× as long as wide, abruptly contracted to a short stipe at the base.
                                         20 Perigynia distinctly 20-30-veined; beak < 0.5 mm long
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                                         20 Perigynia veinless except for 2 marginal veins; beak > 0.7 mm long
                                16 Leaf sheaths and blades glabrous to scabrous.
                                           21 Achene tip with persistent, enlarged, circular style base
                                           21 Achene tip with at most a short apiculus.
                                             22 Leaf blades scabrous on the upper surface; beak of perigynium recurved
                                             22 Leaf blades glabrous on the upper surface, often with rough margins or tip; beak of perigynium straight.
                                               23 Fronts of sheaths of lower leaves ladder-fibrillose; leaves and sheaths septate-nodulose (sometimes obscurely so)
                                               23 Fronts of leaf sheaths not ladder-fibrillose, sometimes breaking into longitudinal fibers; leaves and sheaths not septate-nodulose.
                                                 24 Perigynia strongly 12-30-veined.
                                                    25 Pistillate scales with 3-7 (-10) veins
                                                    25 Pistillate scales with 1-3 veins.
                                                      26 Leaf blades, at least toward the tip, M-shaped in cross-section when young, the upper surface usually with 2 marginal veins more prominent than the midvein; staminate spikes 1-4
                                                      26 Leaf blades V-shaped in cross-section when young, the upper surface lacking 2 marginal veins more prominent than the midrib; staminate spike 1
                                                 24 Perigynia 0-12-veined.
                                                        27 Proximal pistillate spike pendulous, perigynia usually > 30 per spike; terminal staminate spikes 1-3; [exotic]
                                                        27 Proximal pistillate spike erect, perigynia < 25 per spike; terminal staminate spikes 1; [native].
                                                          28 Plants with at least some pistillate spikes basal; culms much shorter than the leaves
                                                          28 Plants with most pistillate spikes on obvious elongated stems; culms shorter than or longer than the leaves.
                                                            29 Upper leaves with blades > 2 cm long, longer than the sheaths
image of plant
Show caption*© Nathan Aaron, some rights reserved (CC BY), uploaded by Nathan Aaron
                                                            29 Upper leaves bladeless or with blades < 1 cm long and also shorter than the sheaths

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1 Apex of perigynium beak with 2 teeth at least (0.4-) 0.5 mm long.
  2 Perigynia with 2 distinct marginal veins, otherwise veinless or only very faintly veined; leaves not septate-nodulose
  2 Perigynia with 5+ distinct veins; at least proximal leaves septate-nodulose, rarely not.
    3 Perigynia with serrulate wing on margins; spikes usually 20+, sessile, pistillate or androgynous and similar in appearance, forming a dense, ovoid or oblong head, rarely with proximal spike separated
    3 Perigynia without wing on margins; spikes not more than 10, usually at least proximal shortly pedunculate, sometimes subsessile, distal and proximal spikes usually dissimilar in appearance, usually not crowded into a dense head.
      4 Pistillate scales obtuse to acuminate, awnless or at most with a rough apiculus.
        5 Staminate spike usually 1; perigynia 15-20-veined, each 10-20 mm long
        5 Staminate spikes usually 1-3+; perigynia 6-15 (-22)-veined, each 4-10 (-12.5) mm.
          6 Perigynia 6-14 (-15)-veined
          6 Perigynia 14-25-veined
             7 Perigynia narrowly ovate to subglobose, 2-2.5× as long as wide
             7 Perigynia elliptic to ovate, 3-4.5× as long as wide
      4 Pistillate scales, at least some, with a scabrous awn.
               8 Perigynia (9-) 10+ mm long.
                 9 Pistillate spikes cylindric, much longer than wide; staminate spikes (1-) 2-6
                 9 Pistillate spikes globose, ovoid, or cylindric, about as long as wide; staminate spikes usually 1
               8 Perigynia < 9 mm long.
                   10 Upper pistillate scales with awn > ½ as long as the body
                   10 Upper pistillate scales acute to short-awned, awn < ½ as long as the body.
                     11 Beak of perigynia with teeth 1.1-3 mm long
                     11 Beak of perigynia with teeth often < 1 mm long.
                       12 Staminate spikes 1 (-4); perigynium beak > 1.7 mm long
                       12 Staminate spikes 1-6; perigynium beak often < 1.7 mm long.
                          13 Perigynia veined only at base; widest leaves < 4 mm wide
                          13 Perigynium veined to tip of body and often into beak; widest leaves mostly > 4 mm wide.
                            14 Pistillate scales with margins serrulate distally; awn, when present, rough.
                              15 Perigynia 3.1-4.8 × 0.9-1.5 (-1.8) mm; staminate spikes 1-2
                              15 Perigynia 2.5-8 × 1.2-3.5 mm; staminate spikes usually 3-7
                            14 Pistillate scales with margins entire; awn, when present, usually smooth.
                                16 Perigynia 9-15-veined
                                16 Perigynia 14-25-veined.
                                  17 Perigynia narrowly ovate to subglobose, 2-2.5× as long as wide
                                  17 Perigynia elliptic to ovate, 3-4.5× as long as wide
1 Apex of perigynium beak entire, emarginate, or with 2 teeth < 0.5 mm long.
                                    18 Perigynia minutely papillose, at least distally (at 20× magnification).
                                       19 Some roots with yellow-brown felty covering
                                       19 Roots brown or black, without yellow-brown felty covering, rarely with white felty covering.
                                         20 Leaf blades and/or sheaths pubescent, at least at junction of blade and sheath
                                         20 Leaf blades and sheaths glabrous.
                                           21 Terminal spike gynecandrous
                                           21 Terminal spike staminate or androgynous.
                                             22 Pistillate scales obtuse to acuminate or with awn < 1 mm long; staminate scales not awned
                                             22 Lower pistillate scales with awn 1.2-3.5 mm long; staminate scales awned
                                    18 Perigynia not papillose, essentially smooth.
                                               23 Terminal spike gynecandrous.
                                                 24 Perigynia with distinct beak 0.5-4 mm long.
                                                    25 Larger spikes usually with > 50 perigynia; achenes 2-3 mm long
                                                    25 Larger spikes with < 40 perigynia; achenes 1-2 mm long
                                                 24 Perigynia beakless or with beak < 0.5 mm long.
                                                      26 Adaxial side of leaves with 2 marginal veins more prominent than midvein; young leaves M-shaped in cross section.
                                                        27 Perigynia ovoid, usually > 1.5× as long as wide; apex tapered to beak; sheaths of proximal leaves not septate-nodulose
                                                        27 Perigynia subcircular, < 1.2× as long as wide; apex rounded, abruptly beaked; sheaths of proximal leaves septate-nodulose
                                                      26 Adaxial side of leaves without 2 marginal veins more prominent than midvein; young leaves V-shaped or rounded in cross section.
                                                          28 Leaf blades and/or sheaths pubescent, at least at junction of blade and sheath
                                                          28 Leaf blades and sheaths glabrous.
                                                            29 Perigynia erect or ascending
                                                            29 Perigynia ascending, spreading at about right angles, or reflexed when mature
                                               23 Terminal spike staminate or androgynous.
                                                              30 Leaves and/or sheaths pubescent, at least at junction of blade and sheath.
                                                                 31 Larger leaves 8-23 mm wide, only the sheaths pubescent
                                                                 31 Leaves < 8 mm wide, blades and usually also the sheaths pubescent.
                                                                   32 Perigynium beak 0.5-3 mm long, often > 1 mm long, about 1/2 the length of the body; proximal pistillate scales awned
                                                                   32 Perigynium beak absent or not more than 0.5 (-0.7) mm long, not > 1/4 the length of the body; proximal pistillate scales acute, acuminate or cuspidate.
                                                              30 Leaves and sheaths usually glabrous, rarely papillose.
                                                                     33 Style persistent on achene in fruit; larger leaves and sheaths usually at least sparsely septate-nodulose, rarely not.
                                                                       34 Perigynia (9-) 10+ mm long; staminate spike usually 1
                                                                       34 Perigynia < 10 mm long; staminate spikes 1-5 (-7).
                                                                         35 Pistillate scales with margins serrulate distally, apex usually rough-awned.
                                                                           36 Distal pistillate scales with apex acute to short-awned, awn < 1/2 as long as the body
                                                                           36 Distal pistillate scales with apex long-awned, awn > 1/2 as long as the body
                                                                         35 Pistillate scales with margins entire, apex awnless or with short, smooth awn.
                                                                              37 Perigynia not inflated, thick walled, brownish, dull
                                                                              37 Perigynia slightly to strongly inflated, thin walled, yellowish to purplish, shiny
                                                                     33 Style deciduous; larger leaves and sheaths sometimes septate-nodulose, more often not.
                                                                                38 Leaf blades, at least widest, M-shaped in cross section when young, adaxial surface with 2 marginal veins more prominent than midvein.
                                                                                  39 Widest leaf blades 8-23 mm wide, septate-nodulose
                                                                                  39 Widest leaf blades < 6 mm wide, not septate-nodulose.
image of plant
Show caption*© Paul Marcum
                                                                                    40 Pistillate scales awned, longest awn > 0.5 mm long
                                                                                    40 Pistillate scales obtuse to acuminate or short-awned, awn < 0.2 mm long
                                                                                38 Leaf blades V-shaped in cross section when young, adaxial surface without 2 marginal veins more prominent than midvein.
                                                                                      41 Proximal perigynia in each spike spreading at right angles or reflexed at maturity; leaf blades and sheaths sparsely septate-nodulose
                                                                                      41 Proximal perigynia in each spike ascending or spreading-ascending; leaf blades and sheaths not septate-nodulose.
                                                                                        42 Plant base brown or blackish, without trace of red or purple
                                                                                        42 Plant base red or purple tinged, sometimes only sparsely so.
                                                                                           43 Perigynia distinctly veined on faces; pistillate scales brown or black
                                                                                           43 Perigynia veinless or with veins only proximally; pistillate scales white-hyaline or red-brown

Key to Carex, Key F: Subkey in Carex

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1 Apex of perigynium beak terminated by 2 teeth, mostly > 0.5 mm long.
  2 Perigynia > 4× as long as wide (8-15 × 1-3 mm).
    3 Apical teeth of perigynium beak erect; achenes oblong-obovoid or obovoid; at least proximal pistillate scales with 3-5 (-7)-veined center
    3 Apical teeth of perigynium beak reflexed; achenes elongate; pistillate scales with 1-veined center
  2 Perigynia < 4× as long as wide.
      4 Perigynia > (9-) 10 mm long.
        5 Sheaths, at least the proximal sheath fronts, densely tomentose at mouth; apical teeth of perigynium beak often > 1 mm long
        5 Sheaths glabrous; apical teeth of perigynium beak not more than 1 mm.
          6 Perigynia 7-11-, 5-12-, or 12-25-veined
          6 Perigynia 12-34-veined.
             7 Basal and proximal leaf sheaths reddish or purplish
             7 Basal and proximal leaf sheaths yellowish to brown, without trace of red or purple
      4 Perigynia < 10 mm long.
               8 At least proximal pistillate scales with long, rough awn.
                 9 Perigynia with 2 strong marginal veins, otherwise veinless or veined only proximally; leaves not septate-nodulose.
                 9 Perigynia with 5+ strong veins extending length of bodies; leaves septate-nodulose.
                   10 Perigynium beak with apical teeth (0.4-) 0.6-3 mm long, often > 1 mm long
                   10 Perigynium beak with apical teeth < 1 mm long.
                     11 Perigynium body obovoid, widest distally; proximal bract > 3× as long as the inflorescence
                     11 Perigynium body ovoid or lanceoloid or ellipsoid, widest at middle or proximally; proximal bract usually < 2× as long as the inflorescence.
                       12 Perigynium beak 0.9-1.7 mm long; mature perigynia dull
                       12 Perigynium beak 0.2-6 mm long; mature perigynia somewhat glossy
               8 All pistillate scales obtuse to acuminate or cuspidate.
                          13 Culms with some red or purple at base.
                            14 All perigynia erect or ascending; leaves not septate-nodulose
                            14 At least proximal perigynia in each spike spreading or reflexed; leaves sparsely septate-nodulose
                          13 Culms brown or black at base, without trace of red or purple.
                              15 Pistillate scales with 5-7-veined center
                              15 Pistillate scales with 1-3-veined center.
                                16 Leaves not septate-nodulose
                                16 Leaves at least sparingly septate-nodulose
1 Apex of perigynium beak entire, emarginate, or with teeth mostly < 0.5 mm long.
                                  17 Leaf blades variously hairy.
                                    18 Plant brown or black at base
                                    18 Plant with at least some red or purple at base
                                  17 Leaf blades glabrous.
                                       19 Bracts without blades.
image of plant
Show caption*© Gary P. Fleming
                                         20 Leaves < 1 mm wide
                                         20 Leaves much wider, often over 10 mm wide
                                       19 Bracts, at least the proximal, with distinct blade.
                                           21 Young leaves V-shaped or rounded in cross section, adaxial surface without 2 marginal veins more prominent than midvein or other veins.
                                             22 Perigynium beak with 2 distinct terminal teeth, usually > 0.2 mm long.
                                               23 At least proximal pistillate scales awned, awn at least 1/2 as long as body; leaves conspicuously septate-nodulose.
                                                 24 Base of culm strongly red or purple; leaves 2-4 mm wide
                                                 24 Base of culm brown, without or with only trace of red or purple; leaves 4-15 mm wide.
                                                    25 Distal pistillate scales acute, acuminate, or short-awned, awn less than 1/2 length of body
                                                    25 Distal pistillate scales with awn at least about as long as body
                                               23 Pistillate scales obtuse to acuminate, sometimes very shortly awned; leaves not or only weakly septate-nodulose.
                                                      26 Plants with long-creeping rhizomes; leaves usually not septate-nodulose
                                                      26 Plants with short-ascending rhizomes; leaves at least sparingly septate-nodulose.
                                                        27 Proximal perigynia in each spike ascending or spreading-ascending
                                                        27 Proximal perigynia in each spike spreading or reflexed
                                             22 Perigynium beak entire, emarginate, or with 2 apical teeth < 0.2 mm long.
                                                          28 Perigynia rounded at base, sides proximally distinctly convex.
                                                            29 Perigynia with veins slightly prominent
image of plant
Show caption*© Paul Marcum
                                                            29 Perigynia with veins slightly impressed
                                                          28 Perigynia tapering at base, sides straight or only slightly convex proximally.
                                                              30 Perigynia rounded at apex, beakless or with beak < 0.3 mm long.
                                                                 31 Widest leaf blades < 5 mm wide; plants usually not cespitose
                                                                 31 Widest leaf blades usually > 5 mm wide; plants usually cespitose
                                                              30 Perigynia tapering to beak at least > (0.3-) 0.5 mm long.
                                                                   32 Proximal perigynia in each spike spreading at right angles or reflexed at maturity; leaves and sheaths sparsely septate- nodulose
                                                                   32 Proximal perigynia in each spike ascending or spreading-ascending; leaves and sheaths not septate-nodulose.
                                                                     33 Plants usually colonial; perigynia and leaves often papillose
                                                                     33 Plants cespitose; perigynia and leaves not papillose
                                           21 Leaf blades M-shaped in cross section when young, adaxial surface with 2 marginal veins more prominent than midvein and other marginal veins, sometimes apparent only on proximal leaves and on proximal part of blade.
                                                                       34 Perigynium beakless or with beak < 0.5 mm long, entire or with 2 apical teeth < 0.1 mm long.
                                                                         35 Widest leaf blades (usually basal) > 10 mm wide.
                                                                           36 Distal pistillate spikes strongly pendulous, perigynia > 100 per spike; [exotic]
                                                                           36 Distal pistillate spikes erect, perigynia < 30 per spike; [native].
                                                                              37 Perigynia trigonous with rounded angles in cross section
image of plant
Show caption*© Scott Ward
                                                                              37 Perigynia sharply trigonous in cross section
                                                                         35 Widest leaf blades < 10 mm wide.
image of plant
Show caption*© Paul Marcum
                                                                                38 Perigynia not prominently veined, veins somewhat impressed
                                                                                38 Perigynia at least slightly prominently veined or veinless except for 2 marginal veins.
                                                                                  39 Perigynia rounded at base, sides proximally convex
                                                                                  39 Perigynia tapering at base, sides proximally straight, concave or slightly convex.
                                                                                    40 Perigynia transversely wrinkled; leaf sheaths sparsely septate-nodulose
                                                                                    40 Perigynia not transversely wrinkled; leaf sheaths not septate-nodulose.
image of plant
Show caption*© Scott Ward
                                                                                      41 Perigynia sharply trigonous in cross section
                                                                                      41 Perigynia terete or with rounded angles in cross section.
                                                                                        42 Perigynia with 2 marginal veins and not more than 10 veins on faces
                                                                                        42 Perigynia with more than 12 veins.
                                                                                           43 Plants usually colonial, not cespitose; perigynia papillose at least faintly.
                                                                                           43 Plants usually cespitose; perigynia not papillose.
                                                                       34 Perigynium with distinct beak > 0.5 mm, usually with apical teeth > 0.1 mm long.
                                                                                             44 Perigynia with 2 distinct marginal veins, otherwise veinless or with very weak veins proximally.
                                                                                               45 Perigynium beak entire, emarginate, or with apical teeth < 0.1 mm long
                                                                                               45 Perigynium beak with apical teeth 0.2-1 mm.
                                                                                                 46 Perigynium beak usually < 1 mm long.
                                                                                                 46 Perigynium beak sometimes > 2 mm long
                                                                                             44 Perigynia with more than 2 veins extending most of length of bodies.
                                                                                                   47 Pistillate scales with narrow, indistinct bodies, scarcely enlarged at bases
                                                                                                   47 Pistillate scales with wide, flat bodies, sometimes terminating in awns.
                                                                                                     48 Perigynium beak entire or emarginate.
                                                                                                        49 Perigynium with not more than 5 veins extending length of body on abaxial face, veinless or weakly veined on adaxial face
                                                                                                        49 Perigynium with > 8 equally prominent veins on both faces.
                                                                                                          50 Perigynia bluntly angled in cross section
                                                                                                          50 Perigynia sharply angled in cross section
                                                                                                     48 Perigynium beak with 2 distinct teeth at apex, usually > 0.2 mm long.
                                                                                                            51 Pistillate spikes, at least the proximal, lax, proximal and middle perigynia separated by internodes at least 1/4 their length; leaves and sheaths not septate-nodulose
                                                                                                            51 Pistillate spikes dense, proximal and middle perigynia separated by internodes less than 1/10 their length; proximal leaves and sheaths sparingly septate-nodulose.
                                                                                                              52 Pistillate scales, at least proximal, awned, awn at least 1/4 of scale body length.
                                                                                                                53 Distal pistillate scales acuminate or with awn less than 1/2 body length; staminate spikes usually 2+
                                                                                                                53 Distal pistillate scales awned, awn usually more than 1/2 body length; staminate spikes 1, sometimes with 1 much smaller spike laterally
                                                                                                              52 Pistillate scales obtuse to acute or apiculate, apiculus not more than 1/10 of body length.
                                                                                                                  54 Culms purple-red at base; achenes with style persistent
                                                                                                                  54 Culms brown at base, without trace of red or purple; achenes with style deciduous