PALINOTAXONOMIA DAS TRIBOS BYTTNERIEAE, HERMANNIEAE E HELICTEREAE (MALVACEAE s. l.) DA FLORA DA BAHIA, BRASIL

Abstract

Palinotaxonomicaly, 27 species of the tribe Byttnerieae, Hermannieae and Helictereae (Malvaceae s. l.) from Bahia State were studied with aim of to increase alow knowledge pollen morphology and to contribute with a taxonomic delimitation of the taxa. The pollen material were acetolysed, analyzed and photographed under light and scanning electron microscopic. Four pollen types are recognized based in exine ornamentation and apertural type: (I) pollen grains (2)3(4)-porate, aspidate, planaperturate, (micro)reticulate exine, whose are representated by the tribe Byttnerieae (Ayenia L., Byttneria L. and Rayleya Cristóbal); (II) pollen grains (2)3-colporate, microreticulate exine, constitute only by Guazuma ulmifolia Lam. (tribe Byttnerieae); (III) pollen grains 3 to 8-colporate, suprareticulate or spinulose exine, represented by Melochia L. and Waltheria L. of the tribe Hermannieae; (IV) pollen grains (2)3(4)-porate, no aspidate, angulaperturate, verrucate or spinulose exine in the species of the tribe Helictereae (Helicteres L.). In the tribe Byttnerieae was observed that Ayenia, Byttneria and Rayleya form a palinotaxonomic complex very homogeneous and in Byttneria and Rayleya were closed related because the reticulate ornamentation of exine. In the tribe Hermannieae, the pollen dimorphism associated the heterostyly of the Melochia and Waltheria species corroborated their proximity. In the tribe Helicterieae, the differentiated morphologic caracterization of Helicteres pollen grains support its taxonomic position in the tribe. The results demonstrated the taxonomic importance of pollen morphology studies corroboring with the subdivision of the taxa subordinates in this tribes.