Carex sect. Obtusatae
in N. L. Britton et al., N. Amer. Fl. 18: 180. 1935.
Plants not cespitose, long-rhizomatous. Culms red-brown to red-purple at base. Leaves: basal sheaths not or only slightly fibrous; sheath fronts membranous, sheath fronts of distal cauline leaves minutely dotted red to purple; blades V-shaped in cross section when young, glabrous. Inflorescence 1 spike; bracts absent; spike androgynous. Proximal pistillate scales less than 10 mm, apex acuminate or cuspidate. Perigynia ascending, brown to reddish black, veinless or obscurely veined, broadly elliptic to obovate, terete to rounded-trigonous in cross section, base rounded-cuneate, apex tapering or rounded to abrupt beak, glabrous; beak 0.5–1 mm, minutely bidentate. Stigmas 3. Achenes rounded-trigonous, almost as large as bodies of perigynia; style deciduous.
w and c North America, Eurasia.
The delimitation of Carex sect. Obtusatae follows T. V. Egorova (1999) who placed C. supina and relatives in sect. Lamprochlaenae (Drejer) L. H. Bailey.