A family of submerged, aquatic herbs, which have leaves in whorls of narrow, forked segments. The flowers are small, unisexual, sessile, and solitary in the leaf axils, with a tiny perianth of many narrow lobes. The male flowers have 10–20 stamens, the females a 1-celled ovary forming a 1-seeded nut. There is 1 genus (Ceratophyllum) and 2 species, cosmopolitan in distribution except for the Arctic.
Subjects: Plant Sciences and Forestry.