Distribution: In Washington, chiefly west of the Cascades, and along the Columbia and Snake Rivers; widespread in central and eastern United States.
Habitat: Mud flats along streams, ponds and lakes.
Flowers: June - September
Conservation Status: Not of concern
Prostrate, sparsely pubescent annual, the hollow culms less than 1 dm. tall, rooting at the nodes.
Sheaths open; ligules a fringe of straight hairs 0.6 mm. long; blades flat to folded, 1-2 mm. broad.
Inflorescence a congested panicle 1.5-6 cm. long, the branches short, bearing spikelets nearly full length; spikelets 9- to 25-flowered, up to 1 cm. long; first glume 1-nerved, 1 mm. long, second glume 3-nerved, nearly 1.5 mm. long; lemmas keeled, distinctly nerved, glabrous, awnless, nearly 2 mm. long; paleas much shorter than the lemmas; anthers exerted.