Juncus exilis Osterhout

Herbs, perennial, cespitose, 3--5 dm. Rhizomes densely branched. Culms (1--)5--15(--25). Cataphylls 1--3. Leaves basal, 2--4; auricles 0.3--0.7 mm, apex usually rounded, scarious to membranaceous; blade flat, 3--15 cm x 0.4--1 mm, margins entire. Inflorescences 3--25-flowered, congested, 1--2.5 x 1--2 cm; primary bract usually exceeding inflorescence. Flowers not secund;: bracteoles 2; tepals dark green to blackish, usually with brownish midstripe, lanceolate to lanceolate-ovate, 3.5--4.3 mm, margins clear; outer and inner series nearly equal; stamens 6, filaments 0.6--0.9 mm, anthers 0.3--0.5 mm; style 0.1 mm. Capsules tan or darker, 3-locular, nearly globose to widely obvoid, 2.5--3.5 x 1.3--1.8 mm, shorter than perianth. Seeds yellowish, obovoid to ellipsioid, 0.4--0.5 mm, not tailed. 2n = 80.

Flowering and fruiting late spring--summer. Moist, open grasslands and meadows; 700--3400 m; Alta., B.C., Sask.; Ariz., Calif., Colo., Idaho, Nev., N.Mex., Mont., Oreg., S.Dak., Utah, Wash., Wyo.