Pollen Morphology and Its Systematic Significance in Sapindaceae from China

Using scanning electron microscopy (SEM), we observed the pollen grains of 30 species and one variety representing 23 genera of Sapindaceae in China. The shapes of the pollen grains of most species in this family were oblate or prolate, rarely spheroidal to subspheroidal in equatorial view and triangular in the polar view. The aperture types were tricolporate, rarely triporate. The pollen exine sculptures were striate or reticulatoid, rarely prickly or granulate. The Xanthoceroideae, broadly defined Lepisanthes,and placement of Delavaya in Dodonaeoideae were supported by the pollen morphology. The close relationships between Boniodendron minus and Koelreuteria,and that among Dimocarpus,Litchi and Nephelium were also supported by the pollen morphology. A key to the genera of Sapindaceae based on the pollen morphology was presented.