Revision of the genera Aleurites, Reutealis and Vernicia (Euphorbiaceae)

The three closely related genera Aleurites J. R. Forst. & G. Forst., Reutealis Airy Shaw and Vernicia Lour., together constituting the subtribe Aleuritinae of the tribe Aleuritideae (Euphorbiaceae subfamily Crotonoideae), are revised. Originally included in Aleurites, Reutealis and Vernicia are considered generically distinct on account of differences in the indumentum, leaf base, inflorescences, number of stamens and fruit type. This distinction has also been confirmed by a recent phylogenetic analysis. Aleurites (2 species) differs from Reutealis and Vernicia by the more numerous stamens arranged in 4 rather than in 2 whorls, and the indehiscent fruits. The monotypic genus Reutealis can easily be distinguished from Aleurites and Vernicia by its five-angular or five-ribbed rather than terete twigs, the presence of rather persistent, hooded bracts, and spatulately flattened rather than terete stigmas. Vernicia (3 species) differs from the other two genera by its large and showy flowers arranged in corymbiform rather than in pyramidal thyrses and the lack of stellate hairs. Moreover, in Vernicia lobed leaves show conspicuous glands at the nadir of each sinus while in Aleurites these glands are absent (leaves of Reutealis are never lobed).