Juncus acutiflorus |
Juncus mertensianus |
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sharpflower rush |
Mertens' rush |
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Habit | Herbs, perennial, rhizomatous, to 8 dm. | Herbs, perennial, rhizomatous to cespitose, 0.5–4 dm. |
Rhizomes | 5–6 mm diam., nodes not swollen. |
1–2 mm diam., not swollen. |
Culms | erect, terete, 3 mm diam., smooth. |
erect, terete, 1–3 mm diam., smooth. |
Cataphylls | 1, straw-colored, apex acute. |
0–1, straw-colored to chestnut brown, apex acute. |
Leaves | basal 1, cauline 2; auricles 0.5 mm, apex rounded, cartilaginous; blade 7–45 cm x 1–2 mm, terete, not scabrous. |
basal 1–2, cauline 0–1; auricles 1–1.2 mm, apex rounded to acute, membranaceous or scarious; blade green to straw-colored, terete, 3–15 cm × 0.3–0.6 mm. |
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. |
terminal single head (rarely cluster of 2 heads), 0.5–1.6 cm; primary bract erect; heads 12–60-flowered, spheric (to hemispheric), 4.5–15 mm diam. |
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. |
tepals dark purplish brown to black, lanceolate to lance-ovate, apex acute, mucro subulate; outer tepals 2.4–4.9 mm; inner tepals 2.3–4.3 mm; stamens 6, anthers 1/4 to equal filament length. |
Capsules | inserted with beak exserted, straw-colored, 1-locular, narrowly ovoid, 2.3–2.4 mm, tapering to subulate tip, valves separating at dehiscence. |
included or slightly exserted, chestnut brown, 1-locular, obovoid, 1.9–3.5 mm, apex obtuse or rounded, valves separating at dehiscence, fertile throughout or only proximal to middle. |
Seeds | narrowly ovoid, 0.5–0.6 mm, not tailed; body clear yellow-brown. |
ellipsoid, 0.4–0.5 mm, not tailed; body clear yellow-brown. |
2n | = 40. |
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Juncus acutiflorus |
Juncus mertensianus |
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Phenology | Fruiting fall. | Fruiting mid summer–fall. |
Habitat | Wet woods | Montane to alpine meadows, stream banks, lake margins, and conifer woods |
Elevation | 0–10 m (0–0 ft) | (400–)1900–3300 m ((1300–)6200–10800 ft) |
Distribution |
NF; SPM; Europe; Asia; Africa |
AK; AZ; CA; CO; ID; MT; NM; NV; OR; UT; WA; WY; AB; BC; NT; SK; YT
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Discussion | Populations from southern California with brown tepals, anthers equaling filaments, and rounded to acute, translucent auricles have been separated as Juncus duranii; the typical form is so highly variable, however, that it can easily accommodate this local form. This species passes into Juncus nevadensis and has often been combined with that species (F. J. Hermann 1964). The two species can generally be separated, and we are following those treatments (F. J. Hermann 1975; A. Cronquist et al. 1972+, vol. 6). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 22. | FNA vol. 22, p. 252. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | J. duranii, J. mertensianus var. duranii, J. mertensianus var. filifolius, J. slwookoorum | |
Name authority | Ehrhart: in G. F. Hoffmann, Deutschl. Fl. 1: 125. (1791) | Bongard: Mém. Acad. Imp. Sci. St.-Pétersbourg, Sér. 6, Sci. Math. 2: 167. (1833) |
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