Juncus polycephalus |
Juncus brevicaudatus |
|
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flatleaf rush, manyhead rush |
narrow-panicle rush, short-tail rush |
|
Habit | Herbs, perennial, cespitose, 6–10 dm. | Herbs, perennial, cespitose, 1.4–5.5(–7) dm. |
Culms | erect, 3–14 mm diam. |
erect, terete, 1–3 mm diam., smooth. |
Cataphylls | absent. |
0–1, straw-colored to pink, apex acute. |
Leaves | basal 2–3(–6), cauline 1–4, brownish green; auricles absent; blade 8–70 cm × 4–8 mm. |
basal 1–3, cauline 1–2; auricles 0.5–3 mm, apex rounded to truncate, scarious; blade terete, 1.5–25 cm × 0.5–2.5 mm. |
Inflorescences | panicles of 16–82 heads, 10–30 cm; primary bract erect; heads 20–30-flowered, spheric, 8–12 mm diam. |
terminal panicles or racemes of 2–35 heads, 1–12 cm, branches erect; primary bract erect; heads 2–8-flowered, ellipsoid to narrowly obconic, 2–9 mm diam. |
Flowers | tepals green to reddish, lance-subulate, 3–4 mm, nearly equal, apex acuminate; stamens 3, anthers 1/3–1/2 length of filaments. |
tepals green to light brown, lanceolate; outer tepals 2.3–3.1 mm, apex acuminate to rarely obtuse; inner tepals 2.5–3.2 mm, apex acuminate; stamens 3 (or 6), anthers 1/4–1/2 filament length. |
Capsules | exserted, straw-colored, 1-locular, narrowly ovoid, 4–5 mm, apex tapering to beak, remaining after dehiscence. |
exserted, chestnut brown, imperfectly 3-locular, narrowly ellipsoid to prismatic, 3.2–4.8 mm, apex acute proximal to beak, valves separating at dehiscence. |
Seeds | lance-ellipsoid, 0.5–0.6 mm, not tailed. |
fusiform, 0.7–1.2 mm, tailed; body covered with whitish translucent veil. |
2n | = 80. |
|
Juncus polycephalus |
Juncus brevicaudatus |
|
Phenology | Fruiting spring–fall. | Fruiting mid summer–fall. |
Habitat | Wet or seasonally wet shores, depressions, occasionally in fairly deep water of streams, usually with a peaty or mucky substrate, occasionally sandy to gravelly | Generally in acidic or peaty moist sites, including emergent shorelines and aroundg hot springs |
Elevation | 0–100 m (0–300 ft) | 100–2500 m (300–8200 ft) |
Distribution |
AL; FL; GA; LA; MD; MS; NC; SC; TX
|
AZ; CO; CT; MA; MD; ME; MI; MN; MT; NC; NH; NY; OR; PA; RI; TN; UT; VA; VT; WI; WV; WY; AB; BC; MB; NB; NL; NS; ON; PE; QC; SK
|
Discussion | Populations from about around hot springs in the west have been separated as Juncus tweedyi Rydberg, but no morphologic distinction appears to exist between J. tweedyi and J. brevicaudatus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Juncaceae > Juncus > subg. Ensifolii | Juncaceae > Juncus > subg. Septati |
Sibling taxa | ||
Synonyms | J. echinatus, J. engelmannii | J. canadensis var. brevicaudatus, J. canadensis var. coarctatus, J. canadensis var. kuntzei, J. coarctatus, J. kuntzei, J. tweedyi |
Name authority | Michaux: Flora Boreali-Americana 1: 192. 1803 (as polycephalos) | (Engelmann) Fernald: Rhodora 6: 35. (1904) |
Web links |