The municipality of Mirandiba, in Pernambuco, is considered a priority area for conservation of Caatinga and has a diverse flora. In this region, the family with the greatest number of species is the Leguminosae, which is represented by about 25% of the species known from the Caatinga. In this study we characterized the pollen grains of the subfamilies Caesalpinioideae and Papilionoideae, and established groups based on pollen morphology. Differences found within the Caesalpinioideae are discussed, especially exine ornamentation, which is striking between the different genera. In Papilionoideae, the most conspicuous difference was the type of aperture, where pores, colpores, and colpi were observed. In the two subfamilies, most genera are considered stenopalynous, making it difficult recognize species by only morphometric characters.
Palynology; Pollen flora; Brazilian semiarid; Caatinga
