A study of pollen morphology, in species of the genera Bauhinia and Phanera (Leguminosae-Caesalpinioideae) which occur in the Brazilian caatinga, is presented. The pollen was examined using light and scanning electron microscopy. Samples were prepared by the KOH method; non-treated pollen grains were examined by scanning electron microscopy. Pollen grains in Bauhinia species (11) are colpate, but porate in B. cheilantha and B. subclavata. All four species of Phanera present colporate pollen

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... ns; P. outimouta is the only to have syncolporate pollen grains. Species of both genera present heteromorphism in the number of apertures. Excepting P. outimouta whose pollen grains are psilate, all species in the two genera present supratectal processes (gemmae/clavae), however the exine in the two genera are different-semitectate, reticulate in Bauhinia species, and tectate, rugulate (or psilate) in Phanera ones. Pollen characters support the segregation of Phanera from Bauhinia.