by Nathaniel Lord Britton & Addison Brown, An Illustrated Flora of the Northern United States… (1913)
“ Ovary 3-celled with axile placentae, or 1-celled with 3 parietal placentae; style filiform or columnar; stigma terminal, entire or minutely toothed; ovules anatropous, numerous, sometimes only 1 of them perfecting. Fruit a many-seeded capsule, or a 1-celled, 1-seeded utricle. Endosperm of the seed copious ; embryo central, cylindric. About 5 genera and 25 species, inhabiting fresh water in the warm and temperate regions of America, Asia and Africa. ”
