Distribution: Widespread in temperate North America; common throughout the Pacific Northwest, but less so than S. acutus.
Habitat: Marshes and muddy shores of lakes and streams at lower elevations; tolerant of alkali.
Flowers: June - August
Conservation Status: Not of concern
Stout, herbaceous perennials from rhizomes, the culms 1-2.5 m. tall, soft, terete.
Leaves few, toward the base of the culm, with well-developed sheath and short blade.
Inflorescence umbel-like, open, with spikelets in small, sessile clusters or singly on the lax branches of the inflorescence; spikelets shiny, reddish-brown, 7-10 mm. long; principle involucral bract solitary, 2-8 cm. long, erect, like an extension of the culm, green; lesser bracts small, chaffy and brownish; scales subtending the flowers scarious, 2.5-3 mm. long, with linear, reddish-brown marks on a brown background, not wholly concealing the achenes; perianth of 2-6 fragile, barbellate bristles; stamens usually 3; style bifid or trifid.
Achenes 2.0-2.3 mm. long, plano-convex or unequally triangular.