Plants 10-40 cm tall. Stem green, obscurely ribbed, densely covered with ramified hairs, becoming glabrous, branched from base; lowest branches whorled; upper branches alternate, obliquely spreading. Leaves sessile, narrowly lanceolate or linear, 1.5-4 cm × 1-7 mm, base attenuate; longitudinal veins 5-7. Spikes axillary, usually 1-3, tower-shaped; bracts ovate, slightly inflexed in fruit, apex acuminate, mucronate. Perianth segments usually 3, narrowly oblong, membranous, apex sometimes 2-lobed. Stamens 5; filaments united at base; anthers oblong, exserted. Utricle cylindric, compressed, not wing-margined distally; beak divided above middle into 2 small, acicular beaks, each with a proximal, lateral, recurved, firm, spinelike, glabrous process. Seed globose, with colored speckles. Fl. and fr. Jun-Sep.