Omphalea is a plant genus of the family Euphorbiaceae and the only genus of its tribe (Omphaleae). It comprises 17 species, all of which are tropical shrubs, trees or lianas. Twelve of them are native to the Americas, 4 are endemic to Madagascar and 1 to Africa. They have monoecious, apetalous flowers and fleshy fruits with hard centers.
The plants are toxic and few animals can eat them. Diurnal moths of the subfamily Uraniinae feed on them. These moths are species of the genus Urania in the Americas, and of the genus Chrysiridia in Africa.
Old World species
The single African species from Tanzania is O. mansfeldiana Mildbraed, a liana. The Madagascan species are O. ankaranensis, a shrub from the limestone karst of northern Madagascar, O. palmata Leandri, a dry forest shrub closely related to O. ankaranensis but from western Madagascar, O. occidentalis Leandri, also a dry forest species of western Madagascar, and O. oppositifilia (Willdenow), a tree from the east coast rainforest of Madagascar.
The Madagascan sunset moth (Chrysiridia rhipheus) feeds on all four of these species.
- Schatz, George E. "Euphorbiaceae - Omphalea oppositifolia". MBG Images of Euphorbiaceae in Madagascar. Missouri Botanical Garden. Retrieved 2008-02-02.
- Gillespie, Lynn J. (1997). "Omphalea (Euphorbiaceae) in Madagascar: A New Species and a New Combination". Novon (St. Louis: Missouri Botanical Garden) 7 (2): 127–136. doi:10.2307/3392184. JSTOR 3392184. Lay summary – JSTOR.