Juncus acutus |
Juncus alpinoarticulatus |
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sharp rush, spiny rush |
alpine rush, northern green rush, northern rush |
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Habit | Herbs, perennial, rhizomatous, 0.5–5 dm. | |
Rhizomes | 2–4 mm diam., not swollen. |
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Culms | erect, terete, 1–3 mm diam., smooth. |
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Cataphylls | 0–1, straw-colored or maroon, apex acute. |
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Leaves | basal 0–2, cauline 1–2(–5); auricles 0.5–1.2 mm, apex rounded, scarious; blade green to straw-colored, terete, 1.5–12 cm × 0.5–1.1 mm. |
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Inflorescences | terminal panicles of 5–25 heads, 3–11 cm, branches erect to ascending; primary bract erect; heads 2–10-flowered, obpyramidal, usually with some flowers short- pedicellateled, 2–6 mm in diam. |
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Flowers | tepals greenish to straw-colored, lanceolate to oblong; outer tepals 1.8–3 mm, apex obtuse, mucronate; inner tepals 1.6–2.7 mm, apex obtuse; stamens 6, anthers 1/2 filament length. |
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Capsules | equaling perianth to usually exserted, chestnut brown to straw-colored, imperfectly 3-locular, oblong to oblong-ovoid, 2.3–3.5 mm, apex obtuse, valves separating at dehiscence. |
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Seeds | oblong to ovoid, 0.5–0.7 mm, not tailed. |
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2n | = 40. |
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Juncus acutus |
Juncus alpinoarticulatus |
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Phenology | Fruiting mid summer–fall. | |
Habitat | Wet meadows, sandy and gravelly, often calcareous shores, fens, and clayey pools over rock | |
Elevation | 0–2600 m (0–8500 ft) | |
Distribution |
AZ; CA; NV; South America; Mexico (Baja Calif); South Africa; Atlantic Islands
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AK; CO; IA; ID; IL; IN; ME; MI; MN; MO; MT; ND; NE; NY; OH; PA; SD; UT; VT; WA; WI; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; Greenland; ; Eurasia
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Discussion | Subspecies 2 (1 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Several attempts have been made to separate subspecies or varieties of this widespread and variable species. In one study, five varieties were recognized, with four in North America (B. Lindquist 1932) . In another, at least six subspecies were recognized with two in North America (L. Hämet-Ahti 1986). The variation we.have encountered does not fit nicely into the subspecies Hämet-Ahti has recognized, and until a full account of the variation throughout the range of the species is presented, we are not recognizing subspecific or varietal divisions of this species. Recent evidence suggests that this species may be one of the parents of the tetraploid Juncus articulatus. Juncus alpinus hybridizes with J. brevicaudatus (= J. × gracilescens J. Hermann), J. articulatus (= J. × alpiniformis Fernald), J. nodosus (= J. × nodosiformis Fernald), and J. torreyi (= JuncusJ. ×stuckeyi Reinking). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 22, p. 237. | FNA vol. 22, p. 254. |
Parent taxa | Juncaceae > Juncus > subg. Juncus | Juncaceae > Juncus > subg. Septati |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | J. alpinus, J.. alpinoarticulatus subsp. americanus, J.. alpinoarticulatus subsp. fuscescens, J.. alpinus var. americanus, J.. alpinus, J.. alpinus var. fuscescens, J.. alpinus var. insignis, J.. alpinus subsp. nodulosus, J.. alpinus var. rariflorus, J.. nodulosus, J.. rariflorus, J.. richardsonianus | |
Name authority | Linnaeus: Sp. Pl. 1: 325. (1753) | Chaix: in D. Villars, Hist. Pl. Dauphiné 1: 378. (1786) |
Web links |