Acevedo-Rodríguez, Pedro & collaborators. 1996. Flora of St. John, U.S. Virgin Islands. Mem. New York Bot. Gard. 78: 1-581.
Genus Description - Erect, fleshy herbs, sometimes woody at base, often with tuberous roots. Leaves alternate, slightly succulent; stipules wanting. Flowers bisexual, actinomorphic, in terminal racemes or panicles; calyx of 2 sepals; petals 5, brightly colored, early deciduous; stamens 5 to numerous, the filaments free, the anthers opening by longitudinal slits; the ovary superior, l-locular, the locules with numerous basal ovules, the styles 3, more or less united, the stigmas linear. Fruit a unilocular loculicidal capsule, opening along 3 valves with numerous reniform to rounded, minute seeds.
Distribution and Ecology - A pantropical genus of about 50 species.