Dioecious, emersed. Rhizome tuberous. Leaves basal; petiole terete; blade linear-lanceolate to ovate, apex acuminate, the base rounded to attenuate. Inflorescence scapose, paniculate, branched, verticillate. Flowers small, sepals persistent; petals white or pinkish, reduced or smaller than sepals; staminate flowers with (6-) 9 stamens and ea. 12 aborted carpels; carpellate flowers with flattened receptacle, occasionally with 2 staminodes, and 8-20 free carpels. Achenes obovoid, laterally compressed, forming a small head.