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.