I gave up on algal taxonomy after I had some 'green mat' algae from my tanks examined by a biologist. Under the microscope, the algae turned out to be a conglomerate of many separate species. The two dominant genera identified by their filamentous branching pattern and caracteristic spores, were Oedogonium and Pithophora (both green algae from the Division Chlorophyta). The Oedogonium appeared to be a mixture of not one, but several species. In addition, blue-green algae Chamaesiphon and Chroococcus species appeared as small blue-green bulbs attached to the green filaments. Finally, there were small populations of diatoms (Division Chrysophyta) and other miscellaneous algal species within the green may. Thus, I decided to use common, descriptive names for algae found in aquariums.