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1 Inflorescence appearing lateral; inflorescence bract erect, appearing to be a continuation of the culm |
1 Inflorescence appearing terminal; inflorescence bract not appearing to be a continuation of the culm. |
..2 Leaf blades non-septate |
..2 Leaf blades septate (sometimes obscure in dried specimens; if so, rest leaf on hard surface and run fingernail over it lengthwise). |
....3 Mature seeds distinctly tailed with elongate appendages at each end (may be obscure in J. subcaudatus), seeds 0.7-2.5 mm long; [subgenus Juncus, section Ozophyllum] |
....3 Mature seeds without appendages, < 0.7 mm long. |
......4 Flowers solitary (rarely up to 3) along branches of inflorescence; flowers often aborted; inflorescence diffuse, with slender flexuous branches; [subgenus Juncus, section Ozophyllum] |
......4 Flowers in heads (glomerules) of 3 or more; flowers seldom aborted; inflorescence various. |
........5 Heads spherical or nearly so, usually 15-60 flowered |
........5 Heads turbinate to hemispherical, 3-15 flowered; [subgenus Juncus, section Ozophyllum] |
1 Flowers borne in heads (glomerules) of 2-6 flowers per head; leaves spine-tipped; single bracteole subtending glomerule present at base of pedicel; [plants of brackish habitats]; [subgenus Juncus, section Juncus] |
..2 Capsule 3.5-5 mm long, obviously longer than the tepals |
..2 Capsule < 3.5 mm long, shorter than or nearly equaling the tepals |
....3 Capsule length nearly equal to perianth length; seeds tailed; [historically known only from Kings County, NY; no longer persisting] |
....3 Capsules distinctly shorter than perianth length; seeds not tailed; [common in coastal marshes; MD s. to FL, w. to TX] |
1 Flowers borne singly on branches of inflorescence; leaves not spine-tipped; each flower subtended by two bracteoles in addition to bracteole at base of pedicel; [plants of various habitats]. |
......4 At least a few sheaths at base of plant with well developed blades; inflorescence bract channeled on one side; [subgenus Agathryon, section Steirochloa] |
......4 Sheaths at base of plant bladeless; bract not channeled; [subgenus Agathryon, section Juncotypus]. |
........5 Culms well spaced along creeping rhizomes. |
..........6 Anthers longer than filaments |
..........6 Anthers shorter than filaments. |
............ 7 Rhizomes 1.5-2 mm diameter; culms 1 mm diameter; inflorescence 3-12 flowered; [boreal, south to ne. WV] |
............ 7 Rhizomes 2-4 mm diameter; culms 1.5-2.5 mm diameter; inflorescence 8-30+ flowered; [from NC and TN south to Panhandle FL] |
........5 Culms cespitose or tufted on short branching rhizomes. |
............ ..8 Perianth much shorter than capsule (about ½ as long); stamens 6; [from NC and TN south to Panhandle FL] |
............ ..8 Perianth > 3/4 length of capsule; stamens 6 or 3; [collectively widespread]. |
............ ....9 Capsules 3-4 mm long; stamens 6; [rare exotic in piedmont and mountains of VA] |
............ ....9 Capsules 1.5-3.2 mm long; stamens 3; [widespread native]. |
............ ......10 Stems with 10-20 prominent ridges just below the inflorescence, with a firm texture; fresh upper stems dull or matte; dried stems coarsely ridged, ridges visible in high relief at 10×, dried ridges capped with shiny bulging cells; perianth 2.7-3.6 mm long, sepals slightly exceeding the petals and capsule. |
............ ........11 Inflorescence bract sheathes swollen and dilated at the base of the inflorescence; inflorescence bract often reflexed after fruit ripening; sheath bases of leaves on the lower stem warm reddish-brown to brown; infructescences capitate, occasionally lobed; [introduction in few sites in our region] |
............ ........11 Inflorescence bract sheathes narrow and not swollen; inflorescence bract erect after fruit ripening; sheath bases of leaves on the lower stem usually purplish-black, occasionally dark red-brown; infructescences usually open, diffuse; [widespread native] |
............ ......10 Stems with 25-30 relatively inconspicuous ridges just below the inflorescence, with a soft texture, easily compressed; fresh upper stems shiny; dried stems with lower ridges, fine or coarse, ridges visible in low relief at 10×, dried ridges capped with low dull cells; perianth 1.9-2.8 mm long, the sepals equaling the petals. |
............ ..........12 Tepals soft, spreading or curving away from capsule at maturity; leaf sheaths 6-14 cm long, usually dark margined, clasping the stem |
............ ..........12 Tepals hard, tightly appressed to capsule at maturity; leaf sheaths (11-) 15-27 cm long, lacking dark margin, often not clasping the stem |
1 Flowers borne in heads (glomerules) of 2 or more, individual flowers not subtended by two bracteoles (in addition to the bracteole at the base of the pedicel); [subgenus Juncus, section Graminifolii]. |
..2 Perianth 6-10 mm long; plant aquatic, submersed and sterile or emersed/stranded and fertile; stems weak, creeping, mat-forming |
..2 Perianth < 6 mm long; plant of uplands or wetland margins, never submersed; stems erect, never creeping or mat-forming. |
....3 Heads 1-5 (-10) per culm; [calcareous glades inland, east to GA and TN] |
....3 Heads >9 per culm; [collectively widespread]. |
......4 Infructescence usually congested, (1.8-) 2.4-4.7 (-6.4) cm long; greatest distance between adjacent rhizome cataphylls (5.3-) 6.3-10.5 (-13.0) mm; rhizome width (measured between adjacent cataphylls) (0.8-) 1.0-1.4 (-1.9) mm |
......4 Infructescence usually loose, (1.4-) 17.9-103.9 (-145) cm long; greatest distance between adjacent rhizome cataphylls (0.1-) 0.4-3.0 (-4.6) mm; rhizome width (measured between adjacent cataphylls) (0.4-) 1.0-3.5 (-4.5) mm. |
........5 Widest leaf blade (2.6-) 3.1-4.5 (-7.0) mm wide; sheath of lowest leaf (3.2-) 4.3-7.8 (-9.7) cm long; tallest culm (27.2-) 50.8-81.2 (-100.7) cm; anthers (0.5-) 0.6-1.0 (-1.3) mm long, exserted; stem base (3.4-) 5.8-9.6 (-12.0) mm wide |
........5 Widest leaf blade (1.3-) 1.6-2.6 (-3.5) mm wide; sheath of lowest leaf (1.7-) 2.2-3.8 (-4.7) cm long; tallest culm (19.2-) 26.0-44.0 (-56.8) cm; anthers (0.2-) 0.3-0.5 (-0.7) mm long, concealed by tepals; stem base (0.4-) 2.0-4.4 (-6.0) mm wide |
1 Flowers borne singly on branches of inflorescence, individual flowers subtended by two bracteoles (in addition to the bracteole at the base of the pedicel). |
..........6 Plants annual, without coarse roots or persistent leaf bases; [subgenus Agathryon, section Tenageia] |
............ 7 Capsule apex acute to obtuse, usually shorter than or equaling inner tepals; inner tepals acute to subobtuse |
............ 7 Capsule apex more or less truncate, usually exceeding inner tepals; inner tepals obtuse |
..........6 Plants perennial, with coarse roots or persistent leaf bases. |
............ ..8 Auricles 3-6 mm long at summit of leaf sheath. |
............ ....9 Capsules < 3/4 length of perianth; unbranched terminal sections of the inflorescence with 2-5 flowers, the longest distance between the adjacent flowers (excluding the peduncle) 6-11 mm |
............ ....9 Capsules > 3/4 length of perianth; unbranched terminal sections of the inflorescence with 1-3 (-4) flowers, the longest distance between the adjacent flowers (excluding the peduncle) 0.5-5.5 mm |
............ ..8 Auricles < 2 mm long or absent. |
............ ......10 Cauline leaves present in addition to basal leaves; blades flat |
............ ......10 Cauline leaves absent. |
............ ........11 Leaf blades terete or channeled. |
............ ..........12 Capsules 1-locular or pseudo-3-locular, widely elliptic to rounded, apex rounded; seeds 0.3-0.4 mm long |
............ ..........12 Capsules 3-locular, elliptic, apex somewhat truncate; seeds 0.48-0.7 mm long |
............ ........11 Leaf blades flat. |
............ ............ 13 Perianth obtuse apically; capsule chestnut brown or darker; [exotic, ranging south to MD] |
............ ............ 13 Perianth acute to acuminate; capsule light brown or tan; [native]. |
............ ............ ..14 Inflorescence bract shorter than inflorescence; capsules 3-locular. |
............ ............ ....15 Perianth usually 2.5-3.5 mm long; flowers secund; capsules globose to ellipsoid |
............ ............ ....15 Perianth usually (3.3-) 4-5 (-5.7)mm long; flowers not secund; capsules ellipsoid or narrowly so |
............ ............ ......16 Anthers 0.6-0.9 mm long; auricles scarious, to 0.5 mm long; [of c. US, marginally in the w. fringe of our area] |
............ ............ ......16 Anthers 1.2-1.5 mm long; auricles scarious to membranous, 0.2-0.3 mm long; [of granitic flatrocks in the Piedmont from NC, SC, GA, and AL] |
............ ............ ..14 Inflorescence bract longer than inflorescence; capsules 1-locular to falsely 3-locular. |
............ ............ ........17 Auricles yellowish, glossy; perianth spreading in fruit |
............ ............ ........17 Auricles whitish or straw colored, dull; perianth not spreading. |
............ ............ ..........18 Mature capsules pale brown or darker; [of the Coastal Plain] |
............ ............ ..........18 Mature capsules pale tan or darker; [of prairies and plains, east to KY, se TN] |
1 Culms and leaves scabrid, gray-green or blue-green; seeds 2.0-2.5 mm long |
1 Culms and leaves smooth, green; seeds 0.7-2.2 mm long. |
..2 Seeds 1.2-2.2 mm long, seed body < ½ length of seed. |
....3 Mature capsules 3.0-4.0 mm long, < 1.5 mm longer than perianth, light reddish brown to light brown; heads 5-50 flowered |
....3 Mature capsules 4.0-5.0 mm long, 2 mm longer than perianth, dark reddish purple; heads 3-7 flowered |
..2 Seeds 0.7-1.2 mm long, seed body > ½ length of seed. |
......4 Perianth obtuse to subacute, with wide scarious margins |
......4 Perianth acuminate, with narrow scarious margins. |
........5 Inflorescence open, the branches widely spreading; mature capsules dark straw colored; heads 5-20 flowered |
........5 Inflorescence narrow, the branches erect; mature capsules dark brown; heads 2-7 flowered |
1 Leaves flattened, narrowly elliptic in cross-section. |
..2 Leaves with incomplete septae; heads about 10 mm diameter; tips of dehisced capsules united; [subgenus Juncus, section Iridifolii] |
..2 Leaves with complete septae; heads about 12 mm diameter; tips of dehisced capsules split; [subgenus Juncus, section Ozophyllum] |
1 Leaves terete, not at all flattened; [subgenus Juncus, section Ozophyllum]. |
....3 Plants strictly cespitose, without any short, hard, knotty rhizomes; tepals lanceolate |
....3 Plants with at least some short, hard, knotty rhizomes; tepals lanceolate-subulate. |
......4 Capsules shorter than the tepals, clearly included within the tepals at maturity |
......4 Capsules equaling or exceeding the tepals, exserted from or only barely included within the tepals at maturity. |
........5 Capsule valves separating at the apex at maturity; stamens 6. |
..........6 Heads 6-20 flowered, 6-9 mm diameter; auricles cartilaginous, 0.5-1.0 mm long |
..........6 Heads 25-100 flowered, 10-14 mm diameter; auricles membranous, 2.5-4.0 mm long |
........5 Capsule valves remaining united at the apex after dehiscence; stamens 3. |
............ 7 Culms 4-8 mm in diameter near the base, usually > 80 cm tall; inflorescences usually > 15 cm tall, with > 25 heads; largest leaf blades > 25 cm long and > 3 mm in diameter |
............ 7 Culms 1-3 mm in diameter near the base, usually < 80 cm tall; inflorescences usually < 10 cm tall, with < 25 heads; largest leaf blades < 25 cm long and 1-2 mm in diameter. |
............ ..8 Uppermost cauline leaf blade much shorter than its sheath; tepals reddish to reddish brown; outer tepals significantly longer than the inner tepals; basal leaf sheaths and cataphylls deep reddish purple |
............ ..8 Uppermost cauline leaf blade equaling or longer than its sheath; tepals green to straw-colored; outer tepals and inner tepals of similar length; basal leaf sheaths and cataphylls straw-colored to brown. |
............ ....9 Heads lobulate; mature capsule 2.0-3.0 mm long |
............ ....9 Heads spherical, not lobulate; mature capsule 3.0-4.5 mm long |
1 Mature capsules 2 mm or more longer than the perianth, 4.0-5.2 mm long |
1 Mature capsules < 1.5 mm longer than the perianth, or subequal to it. |
|
....3 Proximal culm leaf overtopping inflorescence; culms well spaced along creeping rhizomes; plants often exceed 8 dm tall; [northeastern, south to DE, MD, disjuncts in ne. NC] |
....3 Proximal culm leaf shorter than inflorescence; plants cespitose; plants < 8 dm tall; [collectively widespread]. |
......4 Mature capsules slightly shorter than to slightly longer than the perianth (< 0.5 mm longer); perianth 2.6-3.9 mm long; inflorescence 4-16 cm long; [widespread] |
......4 Mature capsules exceeding the perianth by about 1 mm (> 0.5 mm longer); perianth 1.6-3.0 mm long; inflorescence 2-11 cm long; [northern or montane in our region]. |
........5 Capsule apices acute (rarely obtuse); inner tepals acute to acuminate; inflorescence branches widely ascending to spreading |
........5 Capsule apices rounded or obtuse, mucronate; inner tepals acute to obtuse; inflorescence branches strictly ascending |
..........6 Tepals rounded, ca. half the length of the capsules; 6-10 flowers per glomerule; the inflorescence length similar to its width (or only slightly exceeding) |
..........6 Tepals (at least the outer 3) acute, ± same length as the capsules (or slightly shorter); 3-5 (-12) flowers per glomerule; the inflorescence length much exceeding its width |
|
............ 7 Mature capsules about 1/3 longer than perianth (roughly 1-1.5 mm longer) |
............ 7 Mature capsules equaling or barely exceeding perianth. |
............ ..8 Heads 1-50; capsules 2.4-3.6 mm long |
............ ....9 Perennial, capsules 2.8-3.6 mm long, tepals 2.6-3.6 mm long; [widespread in our area] |
............ ....9 Annual, capsules 2.4-2.5 mm long, tepals 1.9-2.3 mm long; [endemic to the Altamaha Grit, Coastal Plain of GA] |
............ ..8 Heads 30-250; capsules 1.9-2.9 mm long. |
............ ......10 Capsules deep chestnut brown; roots with terminal tubers; inner tepals usually > 2.4 mm long; [southeastern] |
............ ......10 Capsules straw colored; roots without terminal tubers; inner tepals usually 1.7-2.3 mm long; [midwestern, east to w. Panhandle FL and se. TN] |
