Distribution: Mostly west of the Cascades, British Columbia south to California, east to southwest Idaho and Arizona.
Habitat: Ditches, lake margins, meadows and other wet places.
Flowers: Late May - August
Conservation Status: Not of concern
Tufted perennial without rhizomes, the stems 4-8 dm. tall.
Leaves alternate, semi-terete, hollow, with prominent partitions; leaf bases sheathing, the margins of the sheaths free at the tip, forming rounded auricles.
Inflorescence terminal, 5-12 cm. long, longer than the involucral bract, with 5-20 heads, the heads 5-8 mm. broad and 10- to 20-flowered; perianth tawny or greenish-brown, 3-3.5 mm. long, the 6 segments subequal, lanceolate-acuminate; stamens 3; style 1 mm. long.
Capsule equal to the perianth, narrowly ovoid, 3-angled, tapered to the tip.