Structural studies of carpels are rare, even though they are very important for taxonomic and phylogenetic analysis. The aim of this work was to analyze carpel structure of six Cassiinae species. To this end, carpels of flowers at anthesis were processed by embedding in methacrylate. Although specific differences were recorded, we observed a structural pattern that is typical of Leguminosae species, especially in overall morphology, as follows: unicarpellate, unilocular, pluriovulated and stipitate gynoecium, with sutural placentation, and anatropous, bitegmic and crassinucelate ovules. The presence of epidermis in the sutural region connecting abaxial and adaxial surfaces is recognized as an ancestral character. This aspect was verified in all six species, indicating that carpel closure is ontogenetic and produces variable structure related to the maintenance of the epidermis between carpel surfaces.
anatomy; ovary; style; stigma; Leguminosae
