Juncus articulatus |
Juncus hemiendytus |
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joint-leaf rush, jointed rush |
blood rush, dwarf rush, Herman's dwarf rush, Hermann's dwarf rush, juncus hemiendytus |
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Habit | Herbs, perennial, rhizomatous to nearly cespitose, 0.5–6(–10) dm. | Herbs, annual, cespitose, 0.03–0.36 dm. | ||||
Rhizomes | 2–3 mm diam., not swollen. |
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Culms | erect to decumbent (and floating), terete, 1–3 mm diam., smooth. |
to 5. |
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Cataphylls | 1, maroon to straw-colored, apex acute to obtuse. |
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Leaves | basal 0–2, cauline (1–)3–6; auricles 0.5–1 mm, apex rounded, scarious; blade green to straw-colored, terete, 3.5–12 cm × 0.5–1.1 mm. |
to 1.8 cm, 1/2–1 1/3 height of plant. |
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Inflorescences | terminal panicles of 3–30(–50) heads, 3.5–8 cm, branches spreading; primary bract erect; heads 3–10-flowered, obpyramidal to hemispheric, 6–8 mm diam. |
solitary flowers. |
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Flowers | tepals green to straw-colored or dark brown, ovate to lanceolate, 1.8–3 mm; outer tepals with apex acute or acuminate; inner tepals with apex acute acuminate to obtuse; stamens 6, anthers equal to filament length. |
2-merous; : tepals 4(–6), erect to recurved at maturity, reddish, 1.5–3 × 0.5–1.2 mm; outer and outer series nearly equal, apex rounded to acute; stamens 2(–3), filaments 0.5–1.4 mm, anthers 0.3–0.7 mm; style 0.1–0.4 mm, stigma 2(–3), 0.3–1 mm. |
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Capsules | exserted ca. 1 mm beyond perianth, chestnut brown to dark brown, imperfectly 3-locular, ellipsoid or ovoid, 2.8–4 mm, apex acute proximal to beak, valves separating at dehiscence. |
reddish, 2–- or 3-locular, obovoid to ellipsoid or oblate, 1.9–3.5 × 1–2 mm. |
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Seeds | obovoid, 0.5 mm, not tailed. |
ovoid to oblate, 0.3–0.55 mm. |
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2n | = 80. |
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Juncus articulatus |
Juncus hemiendytus |
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Phenology | Fruiting mid summer–fall. | |||||
Habitat | Wet ground in ditches, lake and stream margins, and a variety of other habitats, often a calciphile | |||||
Elevation | 0–3000 m (0–9800 ft) | |||||
Distribution |
AK; AZ; CA; CO; CT; ID; IN; KY; MA; ME; MI; MN; NC; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SD; UT; VA; VT; WA; WV; BC; NB; NF; NS; ON; PE; QC; SPM; Eurasia
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Discussion | Juncus articulatus hybridizes with J. brevicaudatus (= J. ×fulvescens Fernald), J. alpinus (= J. ×alpiniformis Fernald), J. nodosus, and J. canadensis. Juncus articulatus var. obtusatus Engelmann appears to be intermediate with J. alpinus. It has spreading inflorescence branches but obtuse inner tepals. This may represent a backcross with J. alpinus. Recent evidence suggests that J. alpinus is a polyploid species with J. articulatus as one of its parents. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 2 (2 in the flora). (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, p. 232. | ||||
Parent taxa | Juncaceae > Juncus > subg. Septati | Juncaceae > Juncus > subg. Graminifolii | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | J. articulatus var. obtusatus, J. articulatus var. stolonifer, J. lampocarpus | J. brachystylus, J. brachystylus var. uniflorus, J. triformis var. uniflorus | ||||
Name authority | Linnaeus: Sp. Pl. 1: 327. (1753) | F. J. Hermann: Leaflets of Western Botany 5: 118. (1948) | ||||
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