Juncus dubius |
Juncus compressus |
|
---|---|---|
dubius rush, mariposa rush, questionable rush |
compressed rush, round-fruit rush |
|
Habit | Herbs, perennial, rhizomatous, 3–7.5 dm. | Herbs, perennial, to 8 dm. |
Rhizomes | 2–3 mm diam., not swollen. |
short- creeping or densely branching, if densely branching herb appearing cespitose. |
Culms | erect, terete, 2–4 mm diam., smooth or rugulose. |
|
Cataphylls | 1–2, pink to straw-colored, apex acute. |
1–3. |
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 and cauline, 1–2; auricles 0.3–0.5 mm, scarious to membranous; blade flat to slightly channeled, 5–35 cm × 0.8–2 mm, margins entire. |
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. |
5–60-flowered, lax, loose to moderately congested, 1.5–8 cm; primary bract usually exceeding 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. |
bracteoles 2; tepals brownish, ovate to oblong, 1.7–2.7 mm; inner and outer series nearly equal, apex obtuse; stamens 6, filaments 0.5–0.7 mm, anthers 0.6–1 mm; style 0.3 mm. |
Capsules | exserted, chestnut brown, 1-locular, subuloidsubulate, (2.4–)3–3.9 mm, apex tapering to subulate tip, valves separating at dehiscence. |
brown or darker, pseudo-3-locular, widely ellipsoid to obovoid, 2.5–3.5 × 1.4–1.8 mm, exceeding tepals. |
Seeds | obovoid, 0.3–0.4 mm, not tailed. |
light brown, ellipsoid to lunate, 0.35–0.556 mm, not tailed. |
2n | = 40. |
= 44. |
Juncus dubius |
Juncus compressus |
|
Phenology | Fruiting early summer–late fall. | Flowering and fruiting late spring–early summer. |
Habitat | Montane meadows, riverbeds, canyons, aroyos | Disturbed ground, especially ditches, along railroads and banks of canals and roadsides, frequently in saline or alkaline soils |
Elevation | 100–1600 m (300–5200 ft) | 1500–2100 m (4900–6900 ft) |
Distribution |
CA
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CO; MD; ME; MI; MN; MT; ND; NE; NY; UT; WI; WY; MB; NF; NS; ON; QC; Europe; w Asia [Introduced in North America]
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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.) |
|
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | J. rugulosus | J. bulbosus, J. supinus |
Name authority | Engelmann | Jacquin: Enumeratio Stirpium Pleraumque, quae sponte crescung in agro Vindobonensi 60, 235. (1762) |
Web links |