ABSTRACT
This study presents a morphoanatomical analysis of Dyckia ibicuiensis , D. polyclada and D. racinae stamens. Flowers at anthesis were desiccated and their stamens were processed using common light microscopic techniques. Morphologically, the androecium in these species is differentiated by the disposition of the stamens around the gynoecium and by general anther characteristics. Included stamens, with antesepalous filaments different from those of the antepetalous, anthers in a radial disposition, always curved, and sporangia facing the gynoecium characterize D. ibicuiensis and D. racinae . This configuration results from the filament connation, as well as special anatomical characteristics of the anthers, such as the connective with thickenings. In addition, these species are differentiated by the U-shaped thickening in the endothecium. D. polyclada is characterized by its small, free and exserted stamens, with a very short common tube, its anthers, that are not curved or organized around the gynoecium, and its divergent sporangia. The anatomical and morphological characteristics identified here are important for characterization of these species. Considering that the androecium is important in the delimitation of Dyckia , the increased use of these data should be equally important for other species and infrageneric groupings.
Keywords
anatomy; androecium; anther; common tube; connective; Dyckia; endothecial thickening; stamen vasculature
