Culms dark to light green, 1-4 m × 4-12 mm, firm to soft, larger air cavities in distal 1/4, 1-2.5 mm wide. Leaves: sheath fronts mostly delicately pinnate-fibrillose. Inflorescences to 3 times branched, branches sometimes flexible and drooping. Spikelets 4-190, 6-24 × 4 mm. Flowers: perianth bristles (4-)6(-8), equaling to less than 1/2 achene body, rarely rudimentary; styles from 2-fid with few 3-fid at spikelet apex to mostly (or all) 3-fid. Achenes plano-convex or compressed obtusely trigonous.

Fruiting (spring-)summer(-fall). Fresh, often calcareous to brackish marshes, fens, lakes, slow streams, often emergent in water to 1.5 m; 0-2100 m; B.C.; Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Tex., Utah, Wash., Wyo.; n Mexico.

Schoenoplectus acutus var. occidentalis forms sterile hybrids with S. californicus in California (S. G. Smith 1995; see 1. S. tabernaemontani).