Abstract
Chamaecrista irwiniana, a new species of Chamaecrista sect. Absus subsect. Absus ser. Rigidulae, is here described and illustrated. Its morphological affinities, geographical distribution, ecology, conservation status, and information about leaf anatomy are also presented. Additionally, a complete description, distribution, and the first illustration of C. nummulariifolia, an endemic species to the states of Goiás and Minas Gerais, classified as vulnerable according to the IUCN guidelines, are provided.