Pollen grains of Guayana Ericaceae.  A, Bejaria neblinensis, note viscin threads (from Maguire & Pires 60477, type).  B-C, Bejaria sprucei (cited as B. variabilis) (from Maguire 40091).  B: tetrad, note viscin threads.  C: enlargement of surface showing verrucate exine.  D, Ledothamnus guyanensis, light microscope, oil immersion (from Cardona 2677).