Juncus dubius |
Juncus filiformis |
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dubius rush, mariposa rush, questionable rush |
thread rush |
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Habit | Herbs, perennial, rhizomatous, 3–7.5 dm. | Herbs, perennial, 0.2–3.5 dm. |
Rhizomes | 2–3 mm diam., not swollen. |
widely creeping, sparingly branched, 1.5–2 mm diam., nodes closely set. |
Culms | erect, terete, 2–4 mm diam., smooth or rugulose. |
terete, 1 mm diam. |
Cataphylls | 1–2, pink to straw-colored, apex acute. |
several. |
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. |
blade absent. |
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. |
3–10(–12)-flowered, loosely congested, 1–2 cm; primary bract terete, nearly equaling to much longer than culm. |
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. |
pedicellate; bracteoles broadly ovate, tepals light brown or green, lanceolate, 2.5–4.2 mm; inner series loosely subtending capsule at maturity, slightly shorter, margins scarious; stamens 6, filaments 0.5–0.9 mm, anthers 0.5–0.7 mm; style 0.2 mm. |
Capsules | exserted, chestnut brown, 1-locular, subuloidsubulate, (2.4–)3–3.9 mm, apex tapering to subulate tip, valves separating at dehiscence. |
tan, 3-locular, nearly globose, 2.5–3 × 1.8–2.1 mm, shorter than perianth. |
Seeds | obovoid, 0.3–0.4 mm, not tailed. |
amber, 0.5–0.6 mm, not tailed. |
2n | = 40. |
= 40, 70, 80, 84. |
Juncus dubius |
Juncus filiformis |
|
Phenology | Fruiting early summer–late fall. | Flowering and fruiting summer. |
Habitat | Montane meadows, riverbeds, canyons, aroyos | Usually sandy, moist or wet soil along stream banks, pools, lakes or in meadow depressions, rarely in bogs, frequently hidden by larger vegetation |
Elevation | 100–1600 m (300–5200 ft) | 0–3000 m (0–9800 ft) |
Distribution |
CA
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AK; CO; ID; MA; ME; MI; MN; MT; NE; NH; NJ; NY; OR; PA; UT; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT; SPM; Greenland; Eurasia; Atlantic Islands (Iceland)
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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.) |
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Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | J. rugulosus | |
Name authority | Engelmann | Linnaeus: Sp. Pl. 1: 326. (1753) |
Web links |