Juncus tenuis |
Juncus dubius |
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path rush, poverty or slender rush, poverty rush, slender rush |
dubius rush, mariposa rush, questionable rush |
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Habit | Herbs, perennial, tufted, 1.5–5 dm. | Herbs, perennial, rhizomatous, 3–7.5 dm. |
Rhizomes | densely branching. |
2–3 mm diam., not swollen. |
Culms | few–20. |
erect, terete, 2–4 mm diam., smooth or rugulose. |
Cataphylls | 1–2, pink to straw-colored, apex acute. |
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Leaves | basal, (1–)2–3; auricles 2–5 mm, apex acute, membranous; blade flat, 3–12 cm × 0.5–1 mm, margins entire. |
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. |
Inflorescences | 5–40-flowered, borne congested or branch internodes ca. as long as tepals, ssomewhat loose, 1–5 cm; primary bract usually longer than inflorescence. |
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. |
Flowers | bracteoles 2; tepals greenish, lanceolate, 3.3–4.4 mm; outer and inner series nearly equal; stamens 6, filaments 0.5–0.9 mm, anthers 0.1–0.2 mm; style 0.1–0.2 mm. |
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. |
Capsules | tan or light brown, 1-locular to pseudo-3-locular, ellipsoid, (3.3–)3.8–4.7 × (1.1–)1.3–1.7 mm, nearly equal to tepals. |
exserted, chestnut brown, 1-locular, subuloidsubulate, (2.4–)3–3.9 mm, apex tapering to subulate tip, valves separating at dehiscence. |
Seeds | tan, ellipsoid to lunate, (0.52–)5.5–0.65(–0.7) mm, not tailed. |
obovoid, 0.3–0.4 mm, not tailed. |
2n | = 80. |
= 40. |
Juncus tenuis |
Juncus dubius |
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Phenology | Flowering spring–early summer. | Fruiting early summer–late fall. |
Habitat | Exposed or shaded sites in soils ranging from sandy to clayey under moist or drier conditions, oftentimes these sites naturally or otherwise disturbed (e.g., game or human trails) | Montane meadows, riverbeds, canyons, aroyos |
Elevation | 100–1600 m (300–5200 ft) | |
Distribution |
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; ON; PE; QC; SK [Introduced worldwide]
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CA
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Discussion | Juncus tenuis occurs throughout North America. It is particularly abundant in northeastern United States and eastern Canada, although infrequent in the south and west. Through the use of isozyme electrophoresis, hybridization can be demonstrated between various members of the Juncus tenuis complex, including Juncus tenuis, J. anthelatus, J. interior, J. secundus, and J. dichotomus (R. E. Brooks, unpubl.). Juncus ××oronensis is thought to be a hybrid between J. tenuis and J. vaseyi in the northeast. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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 | Juncaceae > Juncus > subg. Poiophylli | Juncaceae > Juncus > subg. Septati |
Sibling taxa | ||
Synonyms | J. bicornis, J. bicornis var. williamsii, J. macer, J. macer, J. macer var. williamsii, J. tenuis var. bicornis, J. tenuis var. multicornis, J. tenuis var. williamsii | J. rugulosus |
Name authority | Willdenow: Sp. Pl. 2(1): 214. (1799) | Engelmann |
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