Morfologia poliníca de Dalechampia L. (Euphorbiaceae)

Abstract

Dalechampia L. with 130 species, it is the only genus of Dalechampiinae, has a Pantropical distribution and Brazil (with about 70 species) as the main center of diversity. The genus is recognized for its pseudantial inflorescence, unique in Euphorbiaceae. However, the identification of several species by conventional morphology is complex and the most recent infrageneric classification proposed for Dalechampia is based almost exclusively on macromorphological characters, therefore, alternatives have been sought for a better understanding of interspecific relationships and that help to identify the taxon. Palynology is an important tool for the taxonomy of Euphorbiaceae. Thus, the objective of this work was to develop a study on the pollen morphology of 28 Dalechampia species belonging to four sections and five subsections and to seek to solve interspecific and infrageneric taxonomic problems. The pollen grains were subjected to the classical acetolysis process, observed under an optical and scanning electron microscope. The measures were tabulated and treated statistically and the qualitative characteristics were listed and compared between the morphologically closest species. It was observed that the pollen characteristics helped to distinguish some species, however it was not possible to make a correlation with the most recent infrageneric classification.