Juncus dubius |
Juncus biglumis |
|
---|---|---|
dubius rush, mariposa rush, questionable rush |
two-flower rush, two-glumed rush |
|
Habit | Herbs, perennial, rhizomatous, 3–7.5 dm. | Herbs, perennial, loosely cespitose, 0.25–1.6 dm. |
Rhizomes | 2–3 mm diam., not swollen. |
|
Culms | erect, terete, 2–4 mm diam., smooth or rugulose. |
nearly terete. |
Cataphylls | 1–2, pink to straw-colored, apex acute. |
2–4. |
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, 1–4; sheaths loose; auricles absent or rounded, 0.5 mm; blade imperfectly septate, ascending, nearly terete, 2–7 cm × 0.5–1.5 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. |
heads, 1–2(–4)-flowered; primary bracts much longer than inflorescence. |
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 brown to blackish, oblong, 2.5–4 mm, apex obtuse; outer and inner series nearly equal; stamens 6, filaments 1–1.5 mm, anthers 0.5–0.7 mm; style deciduous, 0.3–0.4 mm. |
Capsules | exserted, chestnut brown, 1-locular, subuloidsubulate, (2.4–)3–3.9 mm, apex tapering to subulate tip, valves separating at dehiscence. |
pale with dark purplish valve margins, pseudo-3-locular, oblate to narrowly ovoid, 4–5.5 × 1.7–2.3 mm, exceeding perianth, apex retuse. |
Seeds | obovoid, 0.3–0.4 mm, not tailed. |
yellowish tan, fusiform-ovoid, 0.7–0.9 mm, short tailed. |
2n | = 40. |
= 120. |
Juncus dubius |
Juncus biglumis |
|
Phenology | Fruiting early summer–late fall. | Flowering and fruiting summer. |
Habitat | Montane meadows, riverbeds, canyons, aroyos | Wet tundra and mossy margins of ponds and streams, wet gravel and open, rocky slopes in alpine zones |
Elevation | 100–1600 m (300–5200 ft) | 10–3400 m (0–11200 ft) |
Distribution |
CA
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AK; CO; MT; WY; AB; BC; LB; MB; NT; NU; ON; QC; YT; Greenland; n Europe; Asia |
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.) |
|
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | J. rugulosus | |
Name authority | Engelmann | Linnaeus: Sp. Pl. 1: 328. (1753) |
Web links |