Perennial herbs, cushion-forming, glabrous. Stems ±regularly forked, dying back from the base, densely covered with persisting wilted leaves. Leaves regularly, densely, and alternately inserted along stem. Blade equal to or slightly shorter than sheath, flat or canaliculate; margins usually finely dentate. Inflorescence reduced to a single lateral sub-terminal flower. Plants dioecious or rarely with a few perfect flowers. Flower bracteole single. Tepals linear to lanceolate. Staminate flowers long pedicellate, exserted above the cushion; stamens 6, with long linear mucronate anthers on short filaments. Pistillate flowers sessile in axil of subapical leaf; ovary sessile; style long, filiform, with 3 filiform papillose stigmas. Capsule triseptate, sessile, narrowly ellipsoid. Seeds many; outer seed-coat spongy, irregularly wrinkled; inner seed-coat castaneous, hard.