ABSTRACT Solanaceae is represented by herbs, shrubs, trees and climbing plants and has cosmopolitan distribution, with a large number of native species in the Neotropical region. This study aimed to characterize the pollen morphology of ten species of Solanaceae (especially species of Cestrum and Solanum) from Cerrado forest fragments in Brazil, in order to contribute to the palynology, taxonomy and conservation of degraded areas. Pollen grains were acetolysed, measured and photographed using light and scanning electron microscopy. Qualitative data were described, and quantitative data were analyzed statistically according to sample size. Morphologically, the studied pollen grains vary in size (small to medium), amb (subcircular to subtriangular), shape (oblate spheroidal to subprolate), aperture details (very long, long or narrow colpi, rounded or tapered at the polar ends, colpi with margo, sometimes with a fastigium, endoapertures can present costa and median constriction) and ornamentation (psilate, rugulate, striate or microreticulate). We observed rugulate or striate pollen grains without fastigium for Cestrum species, whereas psilate or microreticulate pollen grains with fastigium were observed for Solanum species. Qualitative data on diameters and aperture measurements were also found to be important in characterizing the two genera. The results obtained here confirm Solanaceae as an eurypalynous family.

RESUMO Foram investigados os grãos de pólen de duas espécies de Amaranthaceae e três espécies de Araliaceae ocorrentes em fragmentos florestais remanescentes, contribuindo dessa forma com a palinologia, taxonomia e conservação de áreas degradadas. Os grãos de pólen foram acetolisados, medidos, descritos qualitativamente e fotografados sob microscopia de luz e de varredura. Os dados quantitativos foram analisados por estatística descritiva. Os grãos de pólen das espécies de Amaranthaceae são mônades, pequenos, apolares, esféricos, pantoporados com exina metarreticulada. Os das espécies de Araliaceae são mônades, pequenos a médios, isopolares, âmbito subcircular a subtriangular, oblato-esferoidais a subprolatos, 3-colporados, algumas vezes com vestíbulo, endoaberturas lalongadas e exina microrreticulada. Os dados obtidos confirmam o caráter estenopolínico de Amaranthaceae, no entanto as espécies de Araliaceae apresentam características de abertura dos seus grãos de pólen que podem ser usadas para diferenciá-las.

ABSTRACT We investigated the pollen morphology of two native species of Amaranthaceae and three of Araliaceae from forest fragments in order to contribute with the palynology, taxonomy, and conservation of degraded areas. The pollen grains were acetolyzed, measured, qualitatively described and photographed using light and scanning electron microscopy. Quantitative data were analyzed by descriptive statistics. The pollen grains of Amaranthaceae are monads, small, apolar, spherical, pantoporate, and with metareticulate exine. For Araliaceae, the pollen grains are monads, small to medium, isopolar, subcircular to subtriangular, oblato-spheroidal to subprolate, 3-colporate, sometimes with vestibulum, lalongate endoaperture and microreticulate exine. The pollen data confirmed Amaranthaceae as a stenopalynous family. On the other hand, the species of Araliaceae studied characteristically present pollen grains apertures that can be used to differentiate them.