Juncus filiformis |
Juncus alpinoarticulatus |
|
---|---|---|
thread rush |
alpine rush, northern green rush, northern rush |
|
Habit | Herbs, perennial, 0.2–3.5 dm. | Herbs, perennial, rhizomatous, 0.5–5 dm. |
Rhizomes | widely creeping, sparingly branched, 1.5–2 mm diam., nodes closely set. |
2–4 mm diam., not swollen. |
Culms | terete, 1 mm diam. |
erect, terete, 1–3 mm diam., smooth. |
Cataphylls | several. |
0–1, straw-colored or maroon, apex acute. |
Leaves | blade absent. |
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. |
Inflorescences | 3–10(–12)-flowered, loosely congested, 1–2 cm; primary bract terete, nearly equaling to much longer than culm. |
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. |
Flowers | pedicellate; bracteoles broadly ovate, tepals light brown or green, lanceolate, 2.5–4.2 mm; inner series loosely subtending capsule at maturity, slightly shorter, margins scarious; stamens 6, filaments 0.5–0.9 mm, anthers 0.5–0.7 mm; style 0.2 mm. |
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. |
Capsules | tan, 3-locular, nearly globose, 2.5–3 × 1.8–2.1 mm, shorter than perianth. |
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. |
Seeds | amber, 0.5–0.6 mm, not tailed. |
oblong to ovoid, 0.5–0.7 mm, not tailed. |
2n | = 40, 70, 80, 84. |
= 40. |
Juncus filiformis |
Juncus alpinoarticulatus |
|
Phenology | Flowering and fruiting summer. | Fruiting mid summer–fall. |
Habitat | Usually sandy, moist or wet soil along stream banks, pools, lakes or in meadow depressions, rarely in bogs, frequently hidden by larger vegetation | Wet meadows, sandy and gravelly, often calcareous shores, fens, and clayey pools over rock |
Elevation | 0–3000 m (0–9800 ft) | 0–2600 m (0–8500 ft) |
Distribution |
AK; CO; ID; MA; ME; MI; MN; MT; NE; NH; NJ; NY; OR; PA; UT; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT; SPM; Greenland; Eurasia; Atlantic Islands (Iceland)
|
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
|
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.) |
|
Source | FNA vol. 22. | FNA vol. 22, p. 254. |
Parent taxa | Juncaceae > Juncus > subg. Genuini | 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 | Linnaeus: Sp. Pl. 1: 326. (1753) | Chaix: in D. Villars, Hist. Pl. Dauphiné 1: 378. (1786) |
Web links |