Juncus arcticus |
Juncus occidentalis |
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arctic rush |
prairie rush, slender juncus, western rush |
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Habit | Herbs, perennial, 2–10 dm. | Herbs, perennial, cespitose, 3–6 dm. | ||||||||
Rhizomes | long- creeping. |
densely branching. |
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Culms | erect, 1–3 mm diam. |
few–20. |
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Cataphylls | several. |
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Leaves | blade usually absent (present in var. mexicanus). |
basal, (1–)2–3; auricles 0.5–1(–1.5) mm, apex acutish, membranous; blade flat, 5–15 cm × 0.5–1.3 mm, margins entire. |
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Inflorescences | lateral, 3–many-flowered, loose to congested; primary bract barely exceeding to many times longer than inflorescence. |
5–50-flowered, somewhat loose, 1–7 cm; primary bract usually longer than inflorescence. |
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Flowers | variously pedicellate; bracteoles membranous; tepals chestnut brown or paler, lanceolate, (2.5–)3.3–5.5(–6) mm, margins clear; inner series loosely subtending capsule at maturity; usually slightly shorter, margins scarious to clear, apex acutish to obtuse; stamens 6, filaments 0.2–1.1 mm, anthers 0.9–2.2 mm; style 0.9–1.5 mm. |
bracteoles 2; tepals greenish, lanceolate, (3.5–)5 mm; outer and inner series nearly equal; stamens 6, filaments 0.5–1 mm, anthers 0.1–0.3 mm; style 0.1–0.2 mm. |
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Capsules | 3-locular or infrequently pseudo-3-locular, oblate to narrowly ovoid, 3.5–4(–4.5) mm, equal to or exceeding perianth. |
light brown, 1-locular to pseudo-3-locular, ellipsoid, (3–)5–4.5 × 1.2–1.8 mm, nearly equal to shorter than tepals. |
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Seeds | dark amber, oblate to ellipsoid, 0.6–0.8 mm. |
tan, ellipsoid to lunate, 5.5–0.7 mm, not tailed. |
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2n | = 80. |
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Juncus arcticus |
Juncus occidentalis |
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Phenology | Flowering spring–early summer. | |||||||||
Habitat | Moist, usually exposed sites in clayey or sandy soil around springs, along rivers and streams, and around lakes | |||||||||
Elevation | below 2300 m (below 7500 ft) | |||||||||
Distribution |
AK; AR; AZ; CA; CO; DE; IA; ID; IL; IN; KS; MA; MD; ME; MI; MN; MO; MT; ND; NE; NH; NM; NV; NY; OH; OK; OR; PA; SD; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; NT; NU; ON; PE; QC; SK; YT; Mexico; South America; Asia
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AZ; CA; ID; NV; OR; WA
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Discussion | Numerous entities have been circumscribed and recognized at various nomenclatural ranks by a plethora of authors addressing state or regional floras. In considering the Juncus arcticus-balticus complex as a whole in North America, one is soon confronted with a wide-ranging and obviously polymorphic complex that has not read the literature. It is abundantly clear that the systematics of the group will not be solved on the basis of morphology alone and that resolution of the problem is ripe for molecular investigations. Varieties 3 7 (3 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Juncus occidentalis should perhaps be considered a robust variant of J. tenuis. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 22. | FNA vol. 22. | ||||||||
Parent taxa | Juncaceae > Juncus > subg. Genuini | Juncaceae > Juncus > subg. Poiophylli | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | J. tenuis var. occidentalis, J. tenuis var. congestus | |||||||||
Name authority | Willdenow: Sp. Pl. 2: 206. (1799) | (Coville) Wiegand: Bulletin of the Torrey Botanical Club 27: 521. (1900) | ||||||||
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