HYDROCHARITACEAE (Frogbit Family)

Plants herbaceous perennials, monoecious, dioecious, or less commonly with perfect flowers, sometimes with stolons. Stems short and erect or elongate and branched. Leaves opposite, whorled, or essentially basal, simple. Inflorescences short- to long-pedunculate, 1- to few-flowered cymes enclosed by a spathe of 2 bracts, these sometimes more or less fused together. Flowers actinomorphic or less commonly slightly zygomorphic. Sepals 3, distinct. Petals 3, distinct. Stamens 3 to many, some of them sometimes modified into staminodes. Pistils 1 per flower, of 3–6 or more carpels united to form a compound, inferior, 1-locular ovary. Styles 3–6 or more, sometimes fused at the base, sometimes 2-branched or 2-lobed above, each branch with 1 stigma. Fruits berrylike, with numerous small seeds. Fifteen genera, about 100 species, worldwide.

The Hydrocharitaceae are mostly submerged aquatics, although plants of some genera are sometimes floating-leaved, whereas others often grow emergent on mud. The flowers have a variety of unusual pollination mechanisms. The berrylike fruits usually are submerged at maturity. Most of the species are important wildlife food plants.