Alseis sertaneja is described, illustrated, and its diagnostic characteristics and morphological affinities are presented. The new species has whitish to greyish external bark, deciduous and bullate leaves, a congested inflorescence, and occurs in the Caatinga in the states of Bahia and Minas Gerais, Brazil. A new synonym and lectotype for A. involuta K. Schum., a closely related species, are also provided.