Bailey, L.H. (1949) Manual of Cultivated Plants Revised edition. Macmillan, New York.
Aquatic herb, with milky latex. Flowers bisexual. Sepals 3, persistent. Petals 3, soon falling. Stamens many, the outer sterile. Pistils 3 or 6 (rarely 4 or 8), connate at base; ovaries gradually attenuate into the styles.
Worldwide: 5 species in South America
Zimbabwe: 1 cultivated taxon.