Perennial aquatic or bog plants. Leaves petioled, with rounded to elongate blades. Flowers perfect, 1 to many and spicate, regular to irregular, without bracts, subtended by leaflike spathes. Perianth with a tube, 6-lobed or -parted, petaloid, free from the ovary. Stamens 3 or 6, inserted on the perianth; anthers 2-celled, introrse. Ovary superior, 1- or 3-celled; style 1; stigma 3-lobed or 6 toothed. Fruit a capsule or achene.
Six genera and about 20 species, mostly of warmer parts of the world. (Munz, Flora So. Calif. 1007).