Distribution: Occurring chiefly along the lower Columbia River corridor in Washington; occurring in most of western North America and the southeastern U.S.
Habitat: Along ditches and streams where the soil is moist much of the season.
Conservation Status: Not of concern
Strongly stoloniferous perennial, the culms upright, 4-10 dm. tall, the nodes strongly pubescent.
Sheaths open, long-hairy; articulation below the glumes; ligules 1-1.5 mm. long; blades 3-8 mm. broad, the margins slightly thickened.
Inflorescence a pair of terminal spikes 2-7 cm. long; spikelets 2-flowered, 3-3.5 mm. long, flattened, attached in two rows on one side of a broadened rachis; first glume lacking, or lanceolate and 1.5 mm. long; second glume 3-nerved, about equal to the lower, 1-nerved lemma, which is sterile and glabrous; fertile upper lemma and palea hardened, slightly shorter than the sterile lemma; stamens 3; anthers and stigmas purple.