Palynology of Malpighiaceae Juss. In an Area of Ferruginous Campo Rupestre In The Iron Quadrangle, Southeastern Brazil

Serra do Pires, in the Iron Quadrangle (Southeastern Brazil), is a preserved area of ferruginous campo rupestre in a region marked by intense mineral extraction. Malpighiaceae is represented in the area by 14 species whose pollen grains were analyzed to assess their contribution to the taxonomy of the group. The pollen grains were examined under light microscopy and scanning electron microscopy, using statistical treatments and multivariate analysis (PCA and HCA) for data interpretation. The dispersal unit of the monad type was shared by all studied species; the other evaluated characteristics showed variation: amb, aperture, outline, ornamentation, polarity and shape. Based on the results, it was possible to indicate the formation of two groups, one of them grouping the species of Byrsonima, with small, isopolar and 3-colporate pollen grains; and another represented by the species of the genera Banisteriopsis, Camarea, Glicophyllum and Peixotoa, with large, apolar pollen grains; the apertures are of the pore and colpoid type. Such morphological variations, especially size, are interpreted as functional traits associated with transport efficiency and adhesion to pollinators.