XVI International Botanical Congess

Cladophora Ball (Japanese name Marimo, a freshwater green algae) occuring in some lakes in Japan, has been treated as Cladophora aegagropila sensu auct. (Cladophoraceae, Siphonocladales and Cladophorales Complex (SCC), Ulvophyceae). There are many opinions on its taxonomy, and the phylogenetic position is uncertain. We examined the phylogenetic relationships of Ulvophycean taxa based on analyses of 18SrDNA sequences to find the closely related species of Marimo and the phylogenetic position. Our results show that Marimo group being composed of some species of Cladophora, Wittrockiella, Pithophora and Chaetomorpha is monophyletic. Monophyly of every order of Ulvophyceae is confirmed.