Juncus dubius |
Juncus brevicaudatus |
|
---|---|---|
dubius rush, mariposa rush, questionable rush |
narrow-panicle rush, short-tail rush |
|
Habit | Herbs, perennial, rhizomatous, 3–7.5 dm. | Herbs, perennial, cespitose, 1.4–5.5(–7) dm. |
Rhizomes | 2–3 mm diam., not swollen. |
|
Culms | erect, terete, 2–4 mm diam., smooth or rugulose. |
erect, terete, 1–3 mm diam., smooth. |
Cataphylls | 1–2, pink to straw-colored, apex acute. |
0–1, straw-colored to pink, apex acute. |
Leaves | basal 1–2, cauline 1–2; auricles 1–4.9 mm, , apex rounded, membranaceous; blade green to straw-colored, terete, 20–30 cm × 1.5–4 mm, rugulose or smooth. |
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 | terminal panicles of 25–66 heads, 7–13 cm, branches spreading; primary bract erect; heads 6–10-flowered, hemispheric to obovoid, 5–10 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 straw-colored to brown, lanceolate, apex acuminate; outer tepals (2–)2.5–3.4 mm; inner tepals (2–)2.6–3.6 mm; stamens 6, anthers 1.5–2 times filament length. |
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, chestnut brown, 1-locular, subuloidsubulate, (2.4–)3–3.9 mm, apex tapering to subulate tip, valves separating at 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 | obovoid, 0.3–0.4 mm, not tailed. |
fusiform, 0.7–1.2 mm, tailed; body covered with whitish translucent veil. |
2n | = 40. |
= 80. |
Juncus dubius |
Juncus brevicaudatus |
|
Phenology | Fruiting early summer–late fall. | Fruiting mid summer–fall. |
Habitat | Montane meadows, riverbeds, canyons, aroyos | Generally in acidic or peaty moist sites, including emergent shorelines and aroundg hot springs |
Elevation | 100–1600 m (300–5200 ft) | 100–2500 m (300–8200 ft) |
Distribution |
CA
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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
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Discussion | Juncus dubius has rugulose stems and leaves throughout most of its range, but on the periphery (in Mariposa, San Diego, and Sonoma counties, California) the plants are smooth. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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 | ||
Sibling taxa | ||
Synonyms | J. rugulosus | J. canadensis var. brevicaudatus, J. canadensis var. coarctatus, J. canadensis var. kuntzei, J. coarctatus, J. kuntzei, J. tweedyi |
Name authority | Engelmann | (Engelmann) Fernald: Rhodora 6: 35. (1904) |
Web links |