ABSTRACT The aim of this study was to identify plant species visited by Apis mellifera L. in honey producing areas with typical Caatinga vegetation in the State of Bahia, as well as morphologically characterize pollen grains of the most representative species. Flowering specimens were collected from both areas, herborized, identified and deposited at the HUNEB herbarium. Analyses of floristic similarities were performed between eleven municipalities close to the study areas. Pollen was collected from all specimens, acetolyzed, measured, statistically analyzed, morphologically described, and photographed in light microscopy. Of the total of species recorded, 67.46 % were regarded as having beekeeping importance, with the richest botanical families being Fabaceae, Malvaceae and Asteraceae. Additionally, 37.5 % of the recorded species were herbs. The analyzed municipalities showed 84 % of floristic similarity. Of the total species recorded with visits by A. mellifera, 25.52 % had their pollen grains already described in the literature as monads, tetrads and polyads; isopolar, apolar and heteropolar; and mostly prolate spheroidal shape. Sizes varied from small to large, and the amb circular was predominant. The exine ornamentation was greatly diversified, varying from psilate to echinate. The obtained data corroborate the palynological knowledge of plants regarded as having beekeeping importance within the Caatinga.

ABSTRACT The pollen grains of 15 species belonging to five genera (Ceiba Mill., Eriotheca Schott & Endl., Pachira Aubl., Pseudobombax Dugand, and Rhodognaphalopsis A. Robyns) of the subfamily Bombacoideae (Malvaceae s.l.) were acetolysed, measured, described and photomicrographed under light microscopy and scanning and transmission electron microscopy, in order to characterize the pollen morphology of species of the subfamily occurring in Brazil. The pollen characters studied were size, shape, exine constitution, and apertural type. Pollen grains were medium to large-sized and isopolar with a (sub)circular and (sub)triangular amb with flat, convex or concave sides; oblate to suboblate; 3(-4)-colp(or)ate or 4-5(-6)-colporate, planaperturate, sinuaperturate; equatorial calottes different or not; exine tectate or semitectate, perforate and microreticulate with or without supratectal spines. The results confirm the eurypalynous nature of the group with variation among the studied genera being mainly in the exine pattern.

O estudo foi baseado na análise morfológica de espécimes de herbários nacionais e provenientes de coletas. A tribo está representada no Estado por oito gêneros: Actinostemon Sw. (3 spp.), Mabea Aubl. (1sp.), Maprounea Aubl. (1sp.), Microstachys A. Juss.(2 spp.), Sapium P.Browne (2 spp.), Sebastiania Spreng. (1sp.), Senefeldera Mart. (1sp.) e Stillingia Garden ex L. (1sp.). Os gêneros com maior distribuição no Estado são Maprounea, Sapium e Sebastiania, ocorrendo em todas as zonas fitogeográficas. Actinostemon, Mabea e Senefeldera sao restritos a floresta atlantica. São apresentadas chaves para identificação dos gêneros e espécies, descrições, comentários e ilustrações.

The study was based on morphological analysis of specimens from various national herbaria as well as collected material. The tribe is represented in the study area by eight genera: Actinostemon Sw. (3 spp.), Mabea Aubl. (1sp.), Maprounea Aubl. (1sp.), Microstachys A. Juss.(2), Sapium P. Browne (2 spp.), Sebastiania Spreng. (1 spp.), Senefeldera Mart. (1sp.) and Stillingia Garden ex L. (1sp.). Widely distributed genera are Sapium and Sebastiania occurring in all phytogeographical zones. Actinostemon, Senefeldera and Mabea are restricted to the Atlantic rainforest. Identification keys to genera and species, descriptions, illustrations and taxonomic comments are presented.