ABSTRACT
The pollen wall ultrastructure of Tragia capensis and Tragiella natalensis has been studied. In the foveolate-reticulate exine of Tragia capensis, the tectum is thick, the columellae irregular, and the foot layer thick with microchannels. The endexine is thin, unstratified and discontinuous. In the apertural region the most important modifications are in the foot layer First it becomes discontinuous and finally the granulate appearance is noticeable. The endexine is thicker, granulate and lamellate. The semitectate-reticulate exine of Tragiella natalensis presents a well developed ectexine, with undulate tectum, straight columella and foot layer with interruptions and microchannels. The endexine is thin, homogeneous in the inner layer and diffuse in the outer layer. Over the apertures irregular and modified exine patches were also observed. The intine is thick and trilayered around the pollen surface in both species. The phylogenetic implications of these structures is discussed and compared with other Euphorbiaceae taxa.
