Juncus brachycephalus |
Juncus supiniformis |
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small-head rush |
hair-leaf rush, hairy-leaf rush, spreading rush |
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Habit | Herbs, perennial, cespitose, 2–7 dm. | Herbs, perennial, cespitose or matted, often decumbent, rooting at proximal nodes or floating, 0.3–5 dm. |
Culms | erect, 1–4 mm diam., smooth. |
erect, decumbent and rooting at nodes, or floating, terete, 1–2 mm diam., smooth. |
Cataphylls | 1–2, straw-colored to pink, apex acute. |
0 or 1–2, straw-colored, apex acute. |
Leaves | basal 1–3, cauline 1–2; auricles 0.6–1.5 mm, apex rounded, scarious; blade terete to compressed, 0.2–12 cm × 0.5–2 mm. |
basal 1–3, cauline 1–4; auricles 0.8–2.1 mm, apex rounded to acute, membranaceous; blade terete, 3.7–15 cm × 0.4–1.3 mm, occasionally with filiform, flaccid, and floating leaves to 60 cm. |
Inflorescences | panicles of 5–80 heads, 5–25 cm, branches ascending; primary bract erect; heads 2–6-flowered, ellipsoid to obovoid, 2–5 mm diam. |
terminal racemes of 2–9 heads, 2–10 cm, branches erect; primary bract erect; heads 2–12-flowered, obconic or rarely hemispheric, 4–13 mm diam. |
Flowers | tepals green to light brown, lanceolate; outer tepals 1.8–2.5 mm, apex obtuse to nearly acute; inner tepals 2–2.8 mm, apex obtuse to nearly acute; stamens 3 or 6, anthers 1/2 filament length. |
tepals light brown or greenish to reddish brown, linear to narrowly lanceolate, apex acute to acuminate-subulate; outer tepals (2.1–)2.8–4.9 mm; inner tepals (2.1–)2.8–5.5 mm; stamens 3 or 6, anthers 1/2–3/4 filament length. |
Capsules | exserted, chestnut to dark brown, imperfectly 3-locular, obconic, 2.4–3.8 mm, apex acute proximal to beak, valves separating at dehiscence. |
usually exserted, dark brown, 1-locular, ovoid to oblong, (3.2–)3.5–6.1 mm, apex acute to acuminate proximal to beak, valves separating at dehiscence. |
Seeds | ellipsoid to fusiform, 0.8–1.2 mm, tailed; body covered with whitish translucent veil. |
narrowly obovoid to obovoid, 0.6–0.7 mm, not tailed; body clear yellow-brown.. |
n | = ca. 30, ca. 50–60, 2n = ca. 112. |
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2n | = 80. |
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Juncus brachycephalus |
Juncus supiniformis |
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Phenology | Fruiting summer–early fall. | Fruiting mid summer–fall. |
Habitat | Calcareous marshes, wet meadows, and wetland shores | Pond, lake and river shores, marshes, bogs, and ditches |
Elevation | 100–200 m (300–700 ft) | 0–1000 m (0–3300 ft) |
Distribution |
AL; CO; CT; GA; IL; IN; MA; ME; MI; MN; NC; ND; NH; NJ; NY; OH; OK; PA; TN; VA; VT; WI; WV; NB; NS; ON; QC;
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AK; CA; OR; WA; BC
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Discussion | The northern California and southern Oregon populations (Juncus supiniformis in the strict sense) form long filiform leaves before flowering, are shorter, and have smaller flowers than the northern populations. Except for the filiform leaves, the variation in sizes appears to follow a rough latitudinal cline with the largest plants and largest flowers in Alaska. Flowers of Juncus supiniformis often form bulbils. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Juncaceae > Juncus > subg. Septati | Juncaceae > Juncus > subg. Septati |
Sibling taxa | ||
Synonyms | J. canadensis var. brachycephalus | J. oreganus, J. paucicapitatus |
Name authority | (Engelmann) Buchenau: Botanische Jahrbucher fur Systematik, Pflanzengeschichte und Pflanzengeographie 12: 268. (1890) | Engelmann |
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