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The single family of the order Hydrocharitales, characterized by an inferior, compound ovary with laminar placentation.



a family of monocotyledonous plants. They are grasses, wholly or partially submerged in water. The flowers are usually regular, normally trimerous, and sometimes bisexual but more often unisexual (in which case the plants are dioecious). There are three stamens or many; the gynoecia have three to six, more rarely two to 15, carpels; there is an interior ovary. The fruits are mostly berry-like and remain under water. The family comprises about 15 genera and 100 species, which inhabit fresh and marine waters of the temperate, tropical, and subtropical regions.

In the USSR there are six genera and seven species. The best known are water thyme, wild celery, water soldier, and frogbit. Some members of the family are grown in aquariums. Species of the genera Enhalus, Thalassia, and Halophila form extensive underwater thickets in places along the coasts of the Indian, Pacific, and (more rarely) Atlantic oceans. Members of the family Hydrocharitaceae have many diverse adaptations to flowering and pollination; pollination usually occurs under water in freshwater species, and more frequently above water in saltwater species.


Hutchinson, J. The Families of Flowering Plants, 2nd ed., vol. 2. Oxford, 1959.