SEM photomicrographs of Gaultheria erecta pollen (from Luteyn et al. 9389).  Left: polar view of tetrad;  middle: equatorial view;  right: close-up of mesocolpial region (left and middle scale bar = 10 µm;  right bar = 1 µm).  Redrawn from Flora Neotropica Monographs 66: 392, fig. 6A-C.  1995.