General: Perennial grass from conspicuous rhizomes; stems erect to more or less decumbent, hollow, 90-160 (200) cm tall/long.
Leaves: Sheaths smooth, closed completely or open for as much as 1 cm; blades 6-15 mm wide, flat, firm, the upper surfaces minutely rough, smooth on the lower surfaces; ligules blunt, nearly entire, 4-9 mm long.
Flowers: Inflorescence an open, loose panicle, 20-35 cm long, the branches numerous, spreading; spikelets loosely (4-) 5- to 6- (7-) flowered, flattened slightly, egg-shaped, about 4.5 mm long and 1.8 mm wide; glumes lanceolate, the lower ones 1.5-1.7 (2) mm long, the upper ones about (2.3) 2.4-2.6 (3) mm long, usually more or less minutely fringed with fine hairs, the margins sometimes slightly irregularly jagged; lemmas prominently 7-nerved, purplish, about 2.1-2.7 mm long, somewhat irregularly jagged at the blunt tips; paleas abruptly notched, the notches wide, V-shaped, or the margins sometimes slightly irregularly jagged, concealed by the lemmas; stamens 3, sometimes 2; anthers mostly 0.5-0.8 mm long.
Swamps, lakeshores, streamsides and wet meadows in the lowland, steppe and montane zones; frequent in S BC, infrequent northward; N to AK, YT and NT, E to NF and S to ME, MA, VA, OH, IL, IA, NE, NM, AZ and CA.
