Carex sect. Filifoliae
in N. L. Britton et al., N. Amer. Fl. 18: 177. 1935.
Plants cespitose, short-rhizomatous. Culms brown at base. Leaves: basal sheaths fibrous; sheath fronts membranous; blades filiform or V-shaped in cross-section when young, glabrous. Inflorescences a single spike; bracts absent; spike androgynous. Proximal pistillate scales with apex obtuse or mucronate. Perigynia erect or ascending, veinless, or with 2 prominent marginal veins, obovate, ovate, or elliptic, rounded-trigonous in cross-section, base ± tapering or rounded, apex rounded or truncate, to abrupt beak or not, puberulent distally; beak 0.2–1 mm, orifice truncate. Stigmas 3. Achenes trigonous, almost as large as bodies of perigynia; style deciduous.
North America, Mexico
Species 5 (3 in the flora).
|1||Leaf blades folded to channeled, not quill-shaped, 1.5–2 mm wide near base; proximal pistillate scale usually conspicuously long-awned.||Carex oreocharis|
|1||Leaf blades involute-cylindric, quill-shaped, 0.2–0.8 mm wide near base; proximal pistillate scale obtuse to short-awned.||> 2|
|2||Perigynium body glabrous or at most very sparsely short-hirsute near beak; style base not conspicuously exserted from beak, rachilla absent.||Carex elynoides|
|2||Perigynium body short-pubescent, at least on distal 1/4; style base often conspicuously exserted from beak; rachilla present.||Carex filifolia|