Juncus alpinoarticulatus |
Juncus capitatus |
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alpine rush, northern green rush, northern rush |
capitate rush, dwarf rush, leafy-bract dwarf rush |
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Habit | Herbs, perennial, rhizomatous, 0.5–5 dm. | Herbs, annual, cespitose, 0.3–1 dm. |
Rhizomes | 2–4 mm diam., not swollen. |
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Culms | erect, terete, 1–3 mm diam., smooth. |
to 20. |
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. |
basal; auricles absent; blade 0.5–2.5 cm × 0.5 mm. |
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. |
glomerules 1–2, each with 2–10(–14) flowers; bracts subtending inflorescence 1(–2), foliose, clearly surpassing inflorescence. |
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. |
tepals 6, tan to brownish, subulate, lanceolate-ovate, 3.5–4.5(–5) mm, 2 times length of inner tepals, margins scarious; inner series delicate, shorter, apex acute; stamens 3, filaments 1 mm, anthers 0.5 mm; style 0.4–0.7 mm. |
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. |
tan to reddish brown, 3-locular, globose to obovoid, 1.2–1.7 mm, shorter than tepals. |
Seeds | oblong to ovoid, 0.5–0.7 mm, not tailed. |
ellipsoid-ovoid, 0.3–0.4 mm. |
2n | = 40. |
= 18. |
Juncus alpinoarticulatus |
Juncus capitatus |
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Phenology | Fruiting mid summer–fall. | Flowering and fruiting spring. |
Habitat | Wet meadows, sandy and gravelly, often calcareous shores, fens, and clayey pools over rock | Moist to wet areas, usually in sandy, often disturbed soil such as roadsides or along trails |
Elevation | 0–2600 m (0–8500 ft) | below 1000 m (below 3300 ft) |
Distribution |
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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CA; LA; OK; TX; native; Africa (north); Europe; Asia (Near East) [Introduced in North America]
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Discussion | 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.) |
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Source | FNA vol. 22, p. 254. | FNA vol. 22. |
Parent taxa | Juncaceae > Juncus > subg. Septati | Juncaceae > Juncus > subg. Graminifolii |
Sibling 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 | Chaix: in D. Villars, Hist. Pl. Dauphiné 1: 378. (1786) | Weigel: Observ. Bot. 28. (1772) |
Web links |