zonoporate , 4 to 5 pores; rugulate, roundish, slightly angular pollen grain ("golf ball")

4 to 5 zonoporate, pore protruding but without vestibulum; psilate

zonoporate (four to six pores), pentagonal pollen grain; thickened arches (arcus) from pore to pore, visible as bands; protruding pores with a wide vestibulum; psilate