Pollen morphology of the genera Curtia Cham. & Schltdl. and Hockinia Gardner (Gentianaceae Juss.)

Abstract

The pollen morphology of the neotropical genera Curtia Cham. & Schltdl. and Hockinia Gardner (Gentianaceae Juss.) was here studied. Eight species have been analyzed: Curtia conferta (Mart.) Knobl., C. diffusa (Mart.) Cham., C. obtusifolia (Spruce ex Benth.) Knobl., C. patula (Mart.) Knobl., C. quadrifolia Maguire, C. tenella (Mart.) Cham., C. verticillaris (Sprengel) Knobl. and Hockinia montana Gardner. The pollen grains were prepared by the ACLAC method, analyzed in scanning electron microscope and light microscope. The investigation is based on herbarium material. The heterostyly was confirmed in Curtia obtusifolia, C. patula and Hockinia montana Gardner. The pollen material of every heterostylous forms was studied separately. The genera presented pollen grains small or medium, in monads; colparates, isopolars; sexine microrreticulate, microrreticulate-spinulose, reticulate, reticulate spinulose or perforate. The results demonstrated certain heterogeneity in the Curtia and, were observed palynological differences, in size, exine ornamentation and apertures, between floral morphs of every heterostylous species. The two genera showed no palynological differences useful to identify them both.