Juncus dubius |
Juncus roemerianus |
|
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dubius rush, mariposa rush, questionable rush |
black needlerush, needle rush, needlegrass rush |
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Habit | Herbs, perennial, rhizomatous, 3–7.5 dm. | Herbs, perennial, 5–15 dm. |
Rhizomes | 2–3 mm diam., not swollen. |
long, thick, scaly. |
Culms | erect, terete, 2–4 mm diam., smooth or rugulose. |
gray-green, 2–5 mm diam. |
Cataphylls | 1–2, pink to straw-colored, apex acute. |
2–5. |
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; auricles absent; blade terete, 40–80 cdm × 1.5–2.5 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. |
sympodial or appearing lateral, glomerules to 150, each with 2–6 perfect or pistillate flowers, congested to open, 4–20 × 5–10 cm; primary bracts terete, 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 pale brown, 2.5–3.3 mm, apex acuminate; outer series acuminate; inner series slightly shorter, acutish; stamens 6, sometimes rudimentary, filaments 0.2–0.7 mm, anthers 1.3–2.5 mm; style 0.3–1 mm. |
Capsules | exserted, chestnut brown, 1-locular, subuloidsubulate, (2.4–)3–3.9 mm, apex tapering to subulate tip, valves separating at dehiscence. |
brown, 3-locular, ovoid to oblate, 1.7–3 × 1.3–1.6 mm, mostly distinctly shorter than perianth, apiculate. |
Seeds | obovoid, 0.3–0.4 mm, not tailed. |
dark brown, ellipsoid, 0.4–0.6 mm, not tailed. |
2n | = 40. |
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Juncus dubius |
Juncus roemerianus |
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Phenology | Fruiting early summer–late fall. | Flowering and fruiting spring–early fall. |
Habitat | Montane meadows, riverbeds, canyons, aroyos | Coastal tidal marshes in dense zonal stands |
Elevation | 100–1600 m (300–5200 ft) | |
Distribution |
CA
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AL; DC; DE; FL; GA; LA; MD; MS; NC; SC; VA; Texas
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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 | Scheele: Linnaea 22:348. (1849) |
Web links |