Distribution: Alaska south to Oregon, chiefly east of the Cascades; east to northeast United States and south to Virginia and New Mexico.
Habitat: Sloughs, damp meadows and stream borders.
Flowers: Late June - Early August
Conservation Status: Not of concern
Strongly rhizomatous perennial, the culms 9-16 dm. tall.
Sheaths smooth, completely closed, or open up to 1 cm.; ligules 4-9 mm. long, obtuse, entire; blades flat, firm, 6-15 mm. broad.
Inflorescence a loose, open panicle 2-3.5 dm. long, the branches spreading, numerous; spikelets loosely 5- to 6-flowered, oblong in outline; glumes papery, lanceolate, 1-nerved, the first about 1.6-1.7 mm. long, the second, 2.5 mm. long; lemmas 2.5-2.7 mm. long, purplish, blunt, prominently 7-nerved to the scarious upper margin, the nerves non-convergent; paleas about equal to the lemmas, abruptly notched; stamens 3, or occasionally 2.