Abstract
Acalypha chaquensis, A. inselbergensis, and A. pedemontana (Euphorbiaceae: Acalyphoideae) are described as new species, and illustrated with line drawings. A. chaquensis is found in northwestern Paraguay and northern Argentina; A. inselbergensis grows on granitic rock outcrops in Pernambuco State, in Brazil, and A. pedemontana is found in the eastern slope of the Cordillera Oriental of the Bolivian Andes. These species belong to subgenus Acalypha, sections Communes (A. chaquensis and A. pedemontana) and Cuspidatae (A. inselbergensis). Comments on the systematics of the morphologically related species are included.