Abstract
Dombeya sevathianii, a new endemic species from Mauritius, is described and illustrated. Based on its morphology, D. sevathianii belongs to the section Assonia as defined by Arenes and is closely related to D. populnea, endemic to La Reunion and Mauritius. These affinities are confirmed by a previous molecular study. The morphological diagnostic features for D. sevathianii are the cupuliform and entire epicalyx, and the absence of staminodes within the androecium. Given its known restricted distribution and small population, the species should be considered Critically Endangered (CR) as per the Red List Criteria of the International Union for the Conservation of Nature.