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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. |
| ......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). |
| ............ 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 |
| ............ 7 Terminal spike staminate or gynecandrous (if gynecandrous, the pistillate flowers more numerous than the pistillate); lateral spikes not much longer than wide |
| ..........6 Perigynia smooth. |
| ............ ..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 |
| ............ ..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). |
| ............ ............ ..........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. |
| ............ ............ ............ ....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) |
| ............ ............ ............ ............ 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. |
| ............ ............ ............ ............ ..26 Spikes not consistently androgynous, the terminal either entirely staminate or pistillate, the lateral spikes irregularly pistillate, or staminate, or mixed |
| ............ ............ ............ ............ ..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 |
| 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. |
| ............ ............ 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 |
| ............ ............ 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 |
| ............ ............ ............ ..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 |
| ............ ............ ............ ............ ........29 Upper leaves bladeless or with blades < 1 cm long and also shorter than the sheaths |
| 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. |
| ............ ............ ............ ............ ............ ............ ......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 |
| 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. |
| ............ ............ ............ ..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 |
| ............ ............ ............ ............ ........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 |
| ............ ............ ............ ............ ............ ............ 37 Perigynia sharply trigonous in cross section |
| ............ ............ ............ ............ ............ ........35 Widest leaf blades < 10 mm wide. |
| ............ ............ ............ ............ ............ ............ ..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. |
| ............ ............ ............ ............ ............ ............ ........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 |
| 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. |
| ........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; [alien, 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. |
| ............ ........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 |
| ........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 alien] |
| ............ ............ 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. |
| ............ ............ ............ ..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] |
| ............ ............ ............ ..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] |
| ............ ............ ............ 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 |
| 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 perignyia bodies |
| ....3 Pistillate scales usually distinctly narrower than perignyia 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 |
| 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. |
| ............ ..........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). |
| ............ ............ ............ ..........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. |
| ............ ............ ............ ............ ............ ..........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) |
| 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. |
| ............ ....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 |
| ............ ....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 |
| 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. |
| ............ ............ ..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 |
| ............ ............ ..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). |
| ............ ............ ....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 |
| 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. |
| ............ ....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] |
| ............ ....9 Perigynium beaks smooth, 1-4.5 mm long; widest leaves 1.5-15 mm wide. |
| ............ ........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]. |
| ............ ..........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 |
| 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). |
| ..........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] |
| 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. |
| ............ ............ ............ ........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 |
| ............ ............ ............ ........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] |