Plants cespitose, short-rhizomatous. Culms 5–25 cm. Leaves involute, curved, 0.5 mm wide. Spike androgynous. Pistillate scales shorter to longer than and as wide as to wider than perigynia, often covering all but beak, margins hyaline, apex obtuse to acute or, occasionally, cuspidate. Perigynia 4.5–6 mm, distal margins finely serrulate; beak tip hyaline.

Fruiting Jun–Aug. Cliffs, talus slopes, rocky knolls; 60–1000 m; B.C.; Alaska, Wash.

W. J. Cody (1996) mapped one locality for Carex circinata in Yukon and also stated that its occurrence is disputed. Carex circinata is unexpectedly absent from the adjacent Russian Far East, where a close relative, C. hakkodensis Franchet, occurs (T. V. Egorova 1999).