Juncus alpinoarticulatus |
Juncus diffusissimus |
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alpine rush, northern green rush, northern rush |
diffuse rush, slim-fruit rush, slim-pod rush |
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Habit | Herbs, perennial, rhizomatous, 0.5–5 dm. | Herbs, perennial, cespitose, 2.5–6.5 dm. |
Rhizomes | 2–4 mm diam., not swollen. |
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Culms | erect, terete, 1–3 mm diam., smooth. |
erect, terete, 1–3 mm diam., smooth. |
Cataphylls | 0–1, straw-colored or maroon, apex acute. |
0–1, maroon or dark green, apex obtuse. |
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 1, cauline 2–3; auricles 1–2.1 mm, apex rounded, membranaceous; blade maroon or dark green, terete to compressed, 3–20 cm × 1–2.4 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. |
terminal panicles of 30–70(–130), 5–20 cm, branches spreading; primary bract erect; ; heads (1–)2–10-flowered, hemispheric or narrower, 5–10 mm diam. |
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 green to straw-colored, lanceolate, apex acute; outer tepals (2–)2.6–3.2 mm; inner tepals (1.8–)2.3–3 mm; stamens 3, anthers 1/2–2/3 filament length. |
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. |
exserted, , straw-colored, 1-locular, linear-lanceoloid, 4–5.2 mm, apex acute, valves separating at dehiscence. |
Seeds | oblong to ovoid, 0.5–0.7 mm, not tailed. |
oblong-ellipsoid, 0.3–0.4 mm, not tailed; body clear yellow-brown. |
2n | = 40. |
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Juncus alpinoarticulatus |
Juncus diffusissimus |
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Phenology | Fruiting mid summer–fall. | Fruiting summer. |
Habitat | Wet meadows, sandy and gravelly, often calcareous shores, fens, and clayey pools over rock | In soft mucky substrates, marshy shores, sloughs, occasionally in wet wooded places, often in shallow water, commonly abundantly colonizing wet, sandy- alluvial outwash in ditches and clearings |
Elevation | 0–2600 m (0–8500 ft) | 10–1000 m (0–3300 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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AL; AR; CA; CT; FL; GA; IL; IN; KS; KY; LA; MD; MO; MS; NC; OH; OK; SC; TN; TX; VA; WA; WV [Probably introduced, South 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. Septati |
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) | Buckley: Proceedings of the Academy of Natural Sciences of Philadelphia 14: 9. (1862) |
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