Juncus brachycephalus |
Juncus cooperi |
|
---|---|---|
small-head rush |
Cooper's rush |
|
Habit | Herbs, perennial, cespitose, 2–7 dm. | Herbs, perennial, robust, tufted, 4–10 dm. |
Rhizomes | short. |
|
Culms | erect, 1–4 mm diam., smooth. |
terete, 1.5–2.5 mm diam. |
Cataphylls | 1–2, straw-colored to pink, apex acute. |
several, reddish brown, often apiculate. |
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, 1–2; auricles essentially absent; blade terete, 10–40 dcm, shorter than culm. |
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. |
glomerules 3–12, each with (1–)2–5 flowers, open, branches unequal, 3–12 cm, primary bract terete or slightly compressed, shorter to longer than inflorescence. |
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 straw-colored to pale green, ovate-lanceolate, 4–5 mm, apex acuminate or setaceous; inner series elliptic, nearly equal, margins wide, scarious, apiculate; stamens 6, filaments 1 mm, anthers 1.5–2 mm; style 1 mm. |
Capsules | exserted, chestnut to dark brown, imperfectly 3-locular, obconic, 2.4–3.8 mm, apex acute proximal to beak, valves separating at dehiscence. |
tan to light reddish brown, 3-locular, ellipsoid, 3.7–4.5 ×1.6–2 mm, mostly shorter than or nearly equal to perianth. |
Seeds | ellipsoid to fusiform, 0.8–1.2 mm, tailed; body covered with whitish translucent veil. |
dark amber, obovoid, body 0.7–1 mm, tails 0.1–0.5 mm. |
2n | = 80. |
|
Juncus brachycephalus |
Juncus cooperi |
|
Phenology | Fruiting summer–early fall. | Flowering and fruiting spring–summer. |
Habitat | Calcareous marshes, wet meadows, and wetland shores | Saline flats and meadows or edges of salt marshes |
Elevation | 100–200 m (300–700 ft) | below 600 m (below 2000 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;
|
AZ; CA; NV; UT; Mexico |
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Juncaceae > Juncus > subg. Septati | Juncaceae > Juncus > subg. Juncus |
Sibling taxa | ||
Synonyms | J. canadensis var. brachycephalus | |
Name authority | (Engelmann) Buchenau: Botanische Jahrbucher fur Systematik, Pflanzengeschichte und Pflanzengeographie 12: 268. (1890) | Engelmann |
Web links |