Notopora schomburgkii pollen.  A: polar view of tetrad, light microscope, oil immersion (from Maguire & Maguire 40417).  B: pollen tetrads in various positions.  C: tetrad in oblique polar view.  D: tetrad in equatorial view, showing psilate exine but with mesocolpial regions becoming coarsely verucate (B-D from Maguire 46150).  Reproduced from the Memoirs of the New York Botanical Garden 29: 198, fig. 91A-D.  1978.