Juncus dubius |
Juncus leiospermus |
|
---|---|---|
dubius rush, mariposa rush, questionable rush |
dwarf rush, red bluff dwarf rush, smooth-seed rush |
|
Habit | Herbs, perennial, rhizomatous, 3–7.5 dm. | Herbs, annual, cespitose, 0.2–1.2 dm. |
Rhizomes | 2–3 mm diam., not swollen. |
|
Culms | erect, terete, 2–4 mm diam., smooth or rugulose. |
to 100, (0.2–)0.4–0.8 mm diam.. |
Cataphylls | 1–2, pink to straw-colored, 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. |
1/3–3/4 height of plant. |
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 clusters, each with 1–7 flowers; bracts subtending inflorescence 2–8, round to acutely ovate, inconspicuous, 0.7–2.4 mm, membranous. |
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 reddish to black, narrowly lanceolate to oblong, 2–4.6 × 0.5–1.4 mm; inner series usually slightly longer than outer, apex obtuse to acuminate; stamens 3, filaments 0.5–1.4 mm, anthers 1–3.2 mm; style persistent, 1.4–4 mm, stigma 1.3–4 mm. |
Capsules | exserted, chestnut brown, 1-locular, subuloidsubulate, (2.4–)3–3.9 mm, apex tapering to subulate tip, valves separating at dehiscence. |
reddish, 3-locular, globose to ellipsoid or oblong, 2–4.5 × 1–3 mm, nearly equal to sepals. |
Seeds | obovoid, 0.3–0.4 mm, not tailed. |
ovoid, 0.35–0.45 mm. |
n | = 16. |
|
2n | = 40. |
|
Juncus dubius |
Juncus leiospermus |
|
Phenology | Fruiting early summer–late fall. | Flowering and fruiting in spring. |
Habitat | Montane meadows, riverbeds, canyons, aroyos | Margins of vernal pools |
Elevation | 100–1600 m (300–5200 ft) | 0–500 m (0–1600 ft) |
Distribution |
CA
|
CA
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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.) |
Plants from Butte and Calaveras Ccounties, California, tend to be smaller and consistently develop only one flower per culm; they may be recognized as Juncus leiospermus var. ahartii Ertter. Of conservation concern. (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. leiospermus var. ahartii |
Name authority | Engelmann | F. J. Hermann: Leaflets of Western Botany 5: 113. (1948) |
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