Carex sect. Hallerianae
in G. Rouy et al., Fl. France 13: 439. 1912.
Plants densely to loosely cespitose, short-rhizomatous. Culms brown or red- or purple-brown at base, sometimes fibrous. Leaves: sheath fronts membranous; blades V-shaped or M-shaped in cross section when young, proximal leaf blade usually with 2 lateral veins more prominent than midvein on adaxial side, papillose or hairy. Inflorescences racemose, with 2–6 spikes; proximal nonbasal bracts with well-developed blades, sheathless or sheath less than 5 mm; lateral spikes pistillate, sometimes basal, pedunculate, prophyllate; terminal spike staminate, rarely gynecandrous. Proximal pistillate scales hyaline, green, or brown, 3–7-veined, apex subobtuse to acuminate, sometimes awned. Perigynia ascending, 12–30-veined with 2, strong marginal veins, stipitate, obovate or ovate, trigonous in cross section, less than 10 mm, base ± tapering, usually with spongy tissue, apex abruptly contracted or tapering to beak, hairy at least distally; beak straight or bent, to 0.6 mm, emarginate. Stigmas 3. Achenes trigonous, usually nearly as large as bodies of perigynia; style deciduous.
s North America to Central America (e Guatemala), s Europe, sw Asia, n Africa.
Species 5 or more (4 in the flora).
|1||Perigynia 3–4.5 mm, proximal shorter than subtending scales; culms often with basal spikes.||> 2|
|1||Perigynia 4–6 mm, all exceeding subtending scales; culms without basal spikes.||> 3|
|2||Faces of perigynia with veins less than 0.1 mm wide, most distinctly narrower than marginal veins; perigynium beak straight or slightly bent; achenes obtuse to truncate at apex.||Carex planostachys|
|2||Faces of perigynia with most veins ca. 0.1 mm wide or wider, about as wide as marginal veins; perigynium beak mostly abruptly bent; achenes retuse at apex.||Carex lativena|
|3||Achenes 3–3.5 × 1.9–2 mm, almost filling bodies of perigynia; hairs on distal part of perigynium short, not exceeding 0.2 mm.||Carex tenax|
|3||Achenes 2.5–2.6 × 1.3–1.7 mm, filling only distal 1/2 of bodies of perigynia; hairs on distal part of perigynium long, many exceeding 0.3 mm.||Carex dasycarpa|