Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast; circumboreal.
Habitat: Marshes, muddy shores, and other wet places.
Growth Duration: Annual, Perennial
Conservation Status: Not of concern
Very slender perennial from slender, branching rhizomes, forming dense tufts; culms filiform, 3-12 cm. tall, the basal sheaths pale or purplish.
Leaves all basal and reduced to sheaths.
Spikelet solitary and terminal, 2.5-7 mm. long, 3- to 15-flowered; scales of the spikelets spirally arranged, 1.5-2.2 mm. long, translucent, with a greenish midrib and paler margins; perianth of 3-4 bristles, equaling the achene, or wanting; stamens 3; style trifid, thickened at the base.
Achenes white to pale gray, 0.7-1.1 mm. long, with a conic tubercle (the thickened base of the style), the body obovoid, longitudinally 8- to 18-ribbed.