Groppo, M. (Herbarium, Instituto de Biociências, Universidade de São Paulo, Caixa Postal 11461, 05422–970, São Paulo, Brazil; groppojr@hotmail.com), J. A. Kallunki (The New York Botanical Garden, Bronx, NY 10458–5126, U.S.A.), & J. R. Pirani (Instituto de Biociências, Universidade de São Paulo, Caixa Postal 11461, 05422–970, São Paulo, Brazil). Synonymy of Hortia arborea with H. brasiliana (Rutaceae) and a new species from Brazil. Brittonia 57: 28– 34. 2005.—A review of the usage of Hortia brasiliana Vand. ex DC. and H. arborea Engl. is given. The first name has been applied incorrectly to a shrubby species which occurs in the “cerrados” and “campos sujos” (Brazilian savannas) in Rondônia, western Minas Gerais, and central Brazil; the second name pertains to an arborescent species in forests of eastern Brazil. The type specimen of H. brasiliana (of which H. arborea is a synonym) is the same as the arborescent species of eastern Brazil. The name Hortia oreadica is here proposed for the shrubby species of central Brazil, a previously undescribed species. A description, the uses, and the local names, as well as an illustration and distribution map of H. oreadica are presented. The name Hortia arborea Engl. is lectotypified.