Juncus acutiflorus Bentham, not Ehrhart

Herbs, perennial, rhizomatous, 3--6 dm. Rhizomes 1--2 mm diam. Culms erect, 2--4 mm diam. Cataphylls 0--1, straw-colored, apex narrowly acute. Leaves: basal 1--3, cauline 3--4, straw-colored; auricles absent; blade 3--20 cm  ã 3--7 mm. Inflorescences panicles of 10--50 heads, 6--20 cm, erect to ascending branches; primary bract erect; heads 3--11-flowered, turbinate to hemispheric, 4--8 mm diam. Flowers: tepals straw-colored, lanceolate, 2.5--3.2 mm, nearly equal, apex acute to narrowly acuminate, mucronate; stamens 6, anthers 0.5--1.5 times length of filaments. Capsules exserted, chestnut brown, 1-locular, broadly lanceoloid to narrowly oblong, 3.3--4.7 mm, apex tapering to beak, separating at dehiscence. Seeds obovoid, 0.5 mm, not tailed.

Fruiting late spring--fall. Stream and lake shores, montane meadows and seasonally emergent wetlands; 100--2000 m; B.C.; Calif., Oreg., Wash.

Juncus oxymeris should be expected in Mexico (Baja California).