Palynology of Gesneriaceae Rich. & Juss. species from Rio de Janeiro state, Brazil

Abstract

This work deals with the study of pollen of 21 species from the family Gesneriaceae found in six genera, divided into three tribes: Beslerieae tribe - Besleria L. (4 spp.) Episcieae tribe - Codonanthe (Mart.) Hanst. (3 spp.) Nematanthus Schrad. (5 spp); Sinningieae tribe - Paliavana Vand. (1 sp.), Sinningia Nees (6 spp.) and Vanhouttea Lem. (2 spp.), occurring in Rio de Janeiro state, Brazil. We aim to characterize and expand the morphological data of the family, at the general or specific level, thus contributing to a more precise delimitation of taxa. The pollen grains were acetolysed, measured, described and illustrated using light microscopy. To see details of the surface and opening, non-acetolysed pollen grains were examined with a scanning electron microscope (SEM). The pollen grains of the species studied ranged from small to medium, suboblate to prolate; they had colpores or colpes and the number of openings was constant for all species (3-aperture). Ornamentation of the sexine ranged from scabrous to perforated, rugulate, microrreticulate and reticulated. The results showed that pollen morphology is well defined for the species studied; it varied within and between tribes and genera, can be used to identify taxa and maintains the eurypalynological character of the family Gesneriaceae.