Some nostocalean cyanoprokaryotes from lentic habitats of Eastern and Southern Africa

The article comprises the second part (Nostocales) of our study of little known planktic and metaphytic cyanoprokaryotes (cyanophytes, cyanobacteria) from ponds, lakes and water reservoirs in East and Southern Africa. The morphology and variation of 17 species was studied, and comments about their ecology and taxonomy are included. Seven new species are defined: Anabaena austro-africana, A. carmichaelii, A. bituri, A. maxima, A. nygaardii, Aphanizomenon capricorni and Cylindrospermopsis helicoidea. In one tropical species, Cylindrospermopsis africana, akinete formation was found and described for the first time. These investigations of cyanoprokaryotic algae from Africa indicate the existence of a specific and unique tropical microflora. Based on our findings we predict that many more taxa will be found in the future