Juncus debilis |
Juncus castaneus |
|
---|---|---|
weak rush |
chestnut rush |
|
Habit | Herbs, perennial, cespitose, 1–2.5 dm. | Herbs, perennial, strongly rhizomatous, 1–4 dm. |
Culms | erect, terete, 1–2 mm diam., smooth. |
solitary, 1–2 mm diam. |
Cataphylls | 0–1, maroon or dark green, apex acute. |
1–2. |
Leaves | basal 0–1, cauline 1–3; auricles 1–1.5 mm, apex rounded, scarious; blade maroon or dark green, terete, 1–12.5 cm × 0.5–1.5 mm. |
partially cauline, 3–5, auricles absent distally, rounded proximally; blade channeled, to 20 cm, reduced distally. |
Inflorescences | terminal panicles of 3–50 heads, 2–8 cm, branches ascending to spreading; primary bract erect; heads 2–10-flowered, obpyramidal, 2–5 mm diam. |
glomerules, 1–3(–5), each with 2–10 flowers; peduncles 0.4–1.5 cm; primary bracts somewhat inflated, usually surpassing inflorescence. |
Flowers | tepals green to straw-colored, lanceolate, 1.8–2.3(–2.5) mm, apex sharply acuminate; stamens 3, 1/2 filament length. |
bracteoles absent; tepals brown or occasionally paler, lanceolate, 4.5–6.6 mm, apex acute to obtuse; inner series slightly shorter; stamens 6, filaments 2.5–3.5 mm, anthers 0.6–1.3 mm; style 1–1.3 mm. |
Capsules | exserted, straw-colored, 1-locular, narrowly ellipsoid to lanceoloid, 2.8–3.7 7(–4.2) mm, apex acute, valves separating at dehiscence. |
chestnut brown, 3-locular, narrowly oblong, 6.5–8.5 × 1.8–2.3 mm. |
Seeds | ellipsoid, 0.3–0.4 mm, not tailed; body clear yellow-brown. |
pale yellow, fusiform, body 0.6–0.7 mm, tails 0.8–1.1 mm. |
2n | = 60, 90, 120. |
|
Juncus debilis |
Juncus castaneus |
|
Phenology | Fruiting summer. | Flowering and fruiting late spring–summer. |
Habitat | Marshy shores, in small streams, swamps, wet clearings, spring runs, commonly in very soft mucky substrates | Tundra, subalpine and alpine bogs and meadows, and along streams in gravelly or clayey soils |
Elevation | 0–700 m (0–2300 ft) | 10–3700 m (0–12100 ft) |
Distribution |
AL; AR; DE; FL; GA; IL; KY; LA; MD; MO; MS; NC; NJ; NY; PA; SC; TN; TX; VA; Mexicos (Chiapas); Central America (Honduras)
|
AK; CO; MT; NM; NV; UT; WY; AB; BC; LB; MB; NT; NU; ON; QC; SK; YT; Greenland; Europe; Asia |
Discussion | Juncus debilis A. Gray is a name being proposed for conservation. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In southern Alaska some plants with several many-flowered heads and capsules about double the length of the perianth have been referred to the Asian Juncus castaneus subsp. leucochlamys. The distinction, however, seems dubious without further investigation. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Juncaceae > Juncus > subg. Septati | Juncaceae > Juncus > subg. Alpini |
Sibling taxa | ||
Synonyms | J. acuminatus var. debilis, J. radicans | J. castaneus var. pallidus, J. castaneus subsp. leucochlamys, J. leucochlamys |
Name authority | A. Gray: Manual 481506. (1848) | Smith: Fl. Brit. 1: 383. (1800) |
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