Juncus cooperi


Trans. Acad. Sci. St. Louis 2: 590. 1868.

Common names: Cooper's rush
Treatment appears in FNA Volume 22.

Herbs, perennial, robust, tufted, 4–10 dm. Rhizomes short. Culms terete, 1.5–2.5 mm diam. Cataphylls several, reddish brown, often apiculate. Leaves basal, 1–2; auricles essentially absent; blade terete, 10–40 dcm, shorter than culm. Inflorescences 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 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 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 dark amber, obovoid, body 0.7–1 mm, tails 0.1–0.5 mm.

Phenology: Flowering and fruiting spring–summer.
Habitat: Saline flats and meadows or edges of salt marshes
Elevation: below 600 m


V22 167-distribution-map.jpg

Ariz., Calif., Nev., Utah, Mexico.


Selected References


Lower Taxa

... more about "Juncus cooperi"
Ralph E. Brooks* +  and Steven E. Clemants* +
Engelmann +
Juncus sect. Juncastrum +  and Juncus subg. Juncastrum +
Cooper's rush +
Ariz. +, Calif. +, Nev. +, Utah +  and Mexico. +
below 600 m +
Saline flats and meadows or edges of salt marshes +
Flowering and fruiting spring–summer. +
Trans. Acad. Sci. St. Louis +
Juncus sect. Acuti +, Juncus sect. Maritimi +, Juncus sect. Thalassii +  and Juncus subg. Thalassii +
Juncus cooperi +
Juncus subg. Juncus +
species +