Juncus acutiflorus |
Juncus castaneus |
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sharpflower rush |
chestnut rush |
|
Habit | Herbs, perennial, rhizomatous, to 8 dm. | Herbs, perennial, strongly rhizomatous, 1–4 dm. |
Rhizomes | 5–6 mm diam., nodes not swollen. |
|
Culms | erect, terete, 3 mm diam., smooth. |
solitary, 1–2 mm diam. |
Cataphylls | 1, straw-colored, apex acute. |
1–2. |
Leaves | basal 1, cauline 2; auricles 0.5 mm, apex rounded, cartilaginous; blade 7–45 cm x 1–2 mm, terete, not scabrous. |
partially cauline, 3–5, auricles absent distally, rounded proximally; blade channeled, to 20 cm, reduced distally. |
Inflorescences | terminal panicles of 70–120 heads, 6–10 cm, branches ascending; primary bract erect; heads 3–5(–8)-flowered, obconic, 2–4 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 dark reddish brown, lanceolate, apex acuminate to subulate tipte; outer tepals 1.9–2.2 mm; inner tepals 2–2.3 mm; stamens 6, anthers 2 times 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 | inserted with beak exserted, straw-colored, 1-locular, narrowly ovoid, 2.3–2.4 mm, tapering to subulate tip, valves separating at dehiscence. |
chestnut brown, 3-locular, narrowly oblong, 6.5–8.5 × 1.8–2.3 mm. |
Seeds | narrowly ovoid, 0.5–0.6 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. |
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Juncus acutiflorus |
Juncus castaneus |
|
Phenology | Fruiting fall. | Flowering and fruiting late spring–summer. |
Habitat | Wet woods | Tundra, subalpine and alpine bogs and meadows, and along streams in gravelly or clayey soils |
Elevation | 0–10 m (0–0 ft) | 10–3700 m (0–12100 ft) |
Distribution |
NF; SPM; Europe; Asia; Africa |
AK; CO; MT; NM; NV; UT; WY; AB; BC; LB; MB; NT; NU; ON; QC; SK; YT; Greenland; Europe; Asia |
Discussion | 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.) |
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Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | J. castaneus var. pallidus, J. castaneus subsp. leucochlamys, J. leucochlamys | |
Name authority | Ehrhart: in G. F. Hoffmann, Deutschl. Fl. 1: 125. (1791) | Smith: Fl. Brit. 1: 383. (1800) |
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