Two new species of Croton L. (Euphorbiaceae) from campos rupestres of Minas Gerais State, Brazil. Two new species of Croton L. (Euphorbiaceae) are described and illustrated. Croton lenheirensis and C. pradensis occur in campo rupestre vegetation on quartzitic soils in the State of Minas Gerais, the former from Serra do Lenheiro in São João del Rei and the later from Serra de São José in Tiradentes. Both localities are within an important center of endemism for Croton sect. Medea (Klotzsch) Baill., which is represented by at least 30 species from South America. Taxonomic characters which circumscribe the Section are subshrub and shrub habit, laciniate or glandular stipules, stellate indumentum, distribution of glands at the margins of either laciniate or entire sepals of the pistillate flowers, and multifid styles. Croton lenheirensis morphologically resembles C. gnidiaceus Baill., but differs by triangular stipules, lack of petals in pistillate flowers and of apressed-stellate trichomes. Croton pradensis shares morphological characters with C. vestitus Spreng. and C. josephinus Müll. Arg., species also represented on Serra de São José flora, but it is easily distinguishable from both by its wooly sparse indumentum and pistillate flowers which present entire eglandular sepals and no petals.