Juncus articulatus |
Juncus patens |
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joint-leaf rush, jointed rush |
California grey rush, gray rush, rush, spreading rush |
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Habit | Herbs, perennial, rhizomatous to nearly cespitose, 0.5–6(–10) dm. | Herbs, perennial, occasionally tufted, occasionally rhizomatous, 3–9 dm. |
Rhizomes | 2–3 mm diam., not swollen. |
, if present, short. |
Culms | erect to decumbent (and floating), terete, 1–3 mm diam., smooth. |
green or glaucous, 1.5–2.5 mm diam. |
Cataphylls | 1, maroon to straw-colored, apex acute to obtuse. |
several. |
Leaves | basal 0–2, cauline (1–)3–6; auricles 0.5–1 mm, apex rounded, scarious; blade green to straw-colored, terete, 3.5–12 cm × 0.5–1.1 mm. |
blade absent. |
Inflorescences | terminal panicles of 3–30(–50) heads, 3.5–8 cm, branches spreading; primary bract erect; heads 3–10-flowered, obpyramidal to hemispheric, 6–8 mm diam. |
lateral, many flowered, loose to congested, 2–9 cm; primary bract exceeding inflorescence. |
Flowers | tepals green to straw-colored or dark brown, ovate to lanceolate, 1.8–3 mm; outer tepals with apex acute or acuminate; inner tepals with apex acute acuminate to obtuse; stamens 6, anthers equal to filament length. |
variously pedicellate; bracteoles membranous; tepals greenish, light brown or reddish, lanceolate, 2.3–3 mm; inner series nearly equal, margins scarious; stamens 6, filaments 0.6–1 mm, anthers 0.4–0.6 mm; style 0.1 mm. |
Capsules | exserted ca. 1 mm beyond perianth, chestnut brown to dark brown, imperfectly 3-locular, ellipsoid or ovoid, 2.8–4 mm, apex acute proximal to beak, valves separating at dehiscence. |
3-locular or pseudo-3-locular, nearly globose, 2–2.7 mm, equal to or exceeding perianth. |
Seeds | obovoid, 0.5 mm, not tailed. |
dark amber, oblate, 0.4–0.5 mm. |
2n | = 80. |
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Juncus articulatus |
Juncus patens |
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Phenology | Fruiting mid summer–fall. | Flowering and fruiting summer. |
Habitat | Wet ground in ditches, lake and stream margins, and a variety of other habitats, often a calciphile | Stream banks, lake or pond shores, ditches, and other wet places in sandy or clayey soils |
Elevation | 0–3000 m (0–9800 ft) | 0–1600 m (0–5200 ft) |
Distribution |
AK; AZ; CA; CO; CT; ID; IN; KY; MA; ME; MI; MN; NC; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SD; UT; VA; VT; WA; WV; BC; NB; NF; NS; ON; PE; QC; SPM; Eurasia
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CA; OR; WA; nw Mexico
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Discussion | Juncus articulatus hybridizes with J. brevicaudatus (= J. ×fulvescens Fernald), J. alpinus (= J. ×alpiniformis Fernald), J. nodosus, and J. canadensis. Juncus articulatus var. obtusatus Engelmann appears to be intermediate with J. alpinus. It has spreading inflorescence branches but obtuse inner tepals. This may represent a backcross with J. alpinus. Recent evidence suggests that J. alpinus is a polyploid species with J. articulatus as one of its parents. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Juncaceae > Juncus > subg. Septati | Juncaceae > Juncus > subg. Genuini |
Sibling taxa | ||
Synonyms | J. articulatus var. obtusatus, J. articulatus var. stolonifer, J. lampocarpus | |
Name authority | Linnaeus: Sp. Pl. 1: 327. (1753) | E. Meyer: Syn. Luzul. 28. (1823) |
Web links |
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