Herbs, perennial or rarely annual, rhizomatous or not rhizomatous, caulescent; turions absent or present. Leaves alternate or nearly opposite, submersed or both submersed and floating, sessile or petiolate; sheath not persisting longer than blade, not leaving circular scar when shed, ligulate, not auriculate, or rarely auriculate; intravaginal squamules scales, more than 2. Inflorescences terminal or axillary, spikes, capitate spikes, or panicles of spikes, not subtended by spathe, pedunculate; peduncle not elongating, not spiraling following fertilization. Flowers bisexual; subtending bracts absent; tepals 4 in 1 series; stamens [2 or] 4, epitepalous, in 1 series; anthers distinct, dehiscing vertically; pollen spheric; pistils 1 or 4, mostly not stipitate, rarely short-stipitate; ovules marginal, orthotropous. Fruits drupaceous. Seeds 1; embryo curved.