-(Synopsis of the genus Acalypha L. (Euphorbiaceae) in the State of São Paulo, Brazil). Euphorbiaceae is one of the largest families of angiosperms, with 246 genera and approximately 6300 species distributed worldwide. Acalypha is the third largest genus of this family, including about 450 species and with a pantropical distribution. This work was based on the analysis of herbarium collections aiming to carry out the survey of species of the genus Acalypha in the State of São Paulo, as well as contribute to the knowledge of the family in the region and provide an identification key for the species of the genus. We recognized 14 species of Acalypha for São Paulo State, of which two represent new for the State records (A. herzogiana and A. velamea).

A critical taxonomic and nomenclatural review of the Brazilian species of Acalypha (Euphorbiaceae, Acalyphoideae) is presented. As a result, 40 species (44 taxa including six subspecies) are accepted, 37 of them native (17 endemic) and three introduced; also, 132 names are considered synonyms, 28 of them for the first time. Two new combinations are proposed: Acalypha brasiliensis subsp. asterotricha and A. brasiliensis subsp. psilophylla, previously considered varieties of A. brasiliensis. Information about types is provided for all the valid names, and 54 lectotypes and one neotype are designated. Identification keys and detailed distribution maps of all the native taxa are also provided.

Abstract—As part of taxonomic studies of the genus Acalypha in eastern Brazil, we describe here a new species, Acalypha almadinensis, from the Atlantic Rain Forest, in the states of Bahia and Minas Gerais. This species is morphologically similar to Acalypha brasiliensis and A. accedens, but differs from both mainly by its fleshy pistillate bracts and vinaceous lower leaf surface.