Pollen Morphology in Psychotria (Rubiaceae, Rubioideae, Psychotrieae) and its taxonomic significance. A preliminary survey.1992. (Opera Botanica, 115). 35 pls.36 p.gr8vo.Paper bd.

The pollen morphology in 168 species of Psychotria (Rubiaceae,Rubioideae, Psychotrieae) has been investigated using light microscopy and, for 61 of the species, scanning electron microscopy. Transmission electron microscopical studies have been carried out for seven of the species. Psychotria is very heterogeneous pollen morphologically and pollen grain characteristics cannot be used for the delimitation of thegenus as now circumscribed. 22 pollen types have been recognized mainly on the basis of aperture morphology, thickness of exine, size of lumina,muri, columellae and bacula, and sculpture. A key to the identification of the pollen types is presented and all types are illustrated.