Schoenoplectus (Rchb.) Palla

Herbs, perennial or annual, cespitose or not, rhizomatous or not. Culms solitary or not, cylindric to strongly trigonous, smooth, glabrous, spongy with internal air cavities. Leaves basal, rarely 1(–2) cauline; sheaths tubular; ligules membranous, glabrous; blades well developed to rudimentary, cross section dorsiventrally flat to C-shaped or laterally compressed, soft, smooth or margins sometimes distally scabrous or spinulose. Inflorescences terminal, capitate to openly paniculate; spikelets 1–100+; involucral bracts 1–5, leaflike, proximal bract erect to spreading. Spikelets terete, 3–25 × 2–5 mm; scales deciduous, 8+, spirally arranged, each subtending flower, or proximal scale empty (sometimes called a bracteole), floral scales with apex entire or 2-fid, midrib usually prolonged into mucro or awn, smooth or abaxial surface scabrous, margins ciliate. Flowers bisexual (basal flowers pistillate in amphicarpic species); perianth of 0–6(–8) bristles, straight or curved, spinulose, straplike, sometimes fringed with soft, blunt hairs, shorter than to somewhat exceeding achene; stamens 3; anthers 3 mm; styles linear, 2–3-fid, base not or scarcely enlarged, deciduous in fruit. Achenes biconvex to trigonous, with apical beak, faintly to prominently rugose or with transverse wavy ridges, 2.5–3.5 mm including 0.1–2 mm beak.