Description from Flora of China
Herbs annual or perennial, aquatic, floating or rooting in substrate. Roots fibrous. Vegetative stems short or creeping, thick. Leaves rosulate or distributed along stem, distichous; petiole mostly distinct, sometimes inflated; leaf sheath usually present; leaf blade emersed or submersed, broadly ovate, lanceolate, or broadly linear, sometimes completely reduced, stomata paracytic. Flowering stems erect, solid, terminating in a leaf, spathe, and inflorescence. Inflorescences paniculate, racemose, spicate, umbellate, or 1-flowered, subtended by a spathelike or tubular leaf sheath; bracts minute or absent. Flowers bisexual, mostly actinomorphic, sometimes zygomorphic. Perianth segments 6, in 2 whorls, petaloid, free or basally connate into a tube. Stamens usually 6 in 2 whorls, rarely 3 or 1, inserted on perianth, often unequal or dissimilar; filaments slender, free; anthers 2-loculed, introrse, dehiscing by longitudinal slits or rarely by pores; pollen grains 2- or 3-nucleate, colpi 1 or 2(or 3), distal or subequatorial. Ovary superior, 3-loculed and placentation axile or 1-loculed and placentation parietal; ovules numerous per locule or 1 and pendulous, anatropous. Style 1; stigma capitate or minutely 3-lobed. Fruit a 3-valved capsule or indehiscent. Seeds small, longitudinally ribbed or smooth; endosperm copious, mealy; embryo central in seed, straight, terete.
Wu Kuo-fang. 1997. Pontederiaceae. In: Wu Kuo-fang, ed., Fl. Reipubl. Popularis Sin. 13(3): 134--141.
Six genera and ca. 40 species: widespread in tropical and subtropical regions; two genera (one introduced) and five species (one introduced) in China.
(Authors: Wu Guofang (吴国芳 Wu Kuo-fang); Charles N. Horn)