Herbs, monoecious, perennial, caespitose or with extended stout rhizomes, with glabrous scales covering the rhizomes. Cataphylls scarious. Culms unbranched, glabrous, pruinose toward the base, the culm a single internode, with a persistent scarious sheath where the culm joins the peduncle of the single spike; the peduncle more slender than the culm and continuous with the culm. The sheath open and overlapping at the base. Spike solitary, terminal, cylindrical to ovoid, compact, with 20–45 flowers, with zones of female and male flowers alternating once or twice along the spike axis, the basal zone mostly female; flowers spirally arranged in 5 ranks, on very short pedicels. Glumes ovate-cuneate, rigid. Tepals 6, outer lateral tepals keeled. Male flowers with 4 stamens. Female flowers with an initially 2-locular ovary and 2 styles but only one carpel developing; styles mostly stigmatic on the adaxial side, feathery with long white stigmatic hairs. Fruit a small nut (structurally an achene), shed with attached tepals and short stout pedicel. Seeds with an irregular pattern of longitudinal lines of convex cells. Culm striated with grooves extending to the base of the chlorenchyma; stomates on sides of or near base of grooves; ridges without a central sclerenchyma rib.
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