Common Buckthorn, Rhamnus cathartica Family: Rhamnaceae Pollen Grain Morphology: Triangular in polar view, furrows long and slender, tricolporate Pollen Grain Size: (polar) 22.0 + 1.1 µm by 20.0 + 1.0 µm February 4, 2015Rhamnaceae, UncategorizedCommon Buckthorn, Rhamnaceae, Rhamnus, Rhamnus cathartica, triangular, tricolporate