Chamaecrista belladonna (Fabaceae, Caesalpinioideae, Cassieae), a new threatened endemic species from Goiás, Brazil

Chamaecrista belladonna is described and illustrated. It is assigned to Chamaecrista sect. Absus subsect. Absus series Microphyllae. The species grows on mixed sand-clay soils near rock outcrops in the Chapada dos Veadeiros region in the Brazilian state of Goiás. Since it is found in an area 0.4 km2, surrounded by agricultural land and under intense anthropogenic pressure, it is here considered Critically Endangered. The novel species can be distinguished from all other species of the series by having pseudo-terminal inflorescences (borne in the axil of the distal-most leaf at the ends of branches and appearing opposite the leaf) with flexuous axis and leaflets with mixed acrodromous-brochidodromous venation. Discussion is provided about the distribution, phenology, and conservation status of the new species, as well as its morphological relationships with the similar species C. dumalis and C. imbricans. Images and descriptions of the leaf anatomy of the new species are also given.