2012 Volume 62 Issue 2_3 Pages 69-78
Two species of Chlamydomonas, Chlamydomonas pseudomacrostigma L. S. Peterfi ex H. Ettl and Chlamydomonas media G. A. Klebs, were examined using light microscopy and the molecular phylogeny of 18S rRNA gene sequences. The molecular phylogeny clearly showed that both species belong to the clade Monadinia and are closely related to Chlamydomonas monadina F. Stein and Chloromonas subdivisa (Pascher & Jahoda) Gerloff & H. Ettl. Based on detailed light microscopy, the chloroplasts of C. pseudomacrostigma were shown to be deep-cup-shaped with a single parietal pyrenoid (Chlamydella-type). Both light microscopy and 18S rRNA gene phylogeny also revealed that an additional strain previously identified as Chlamydomonas monadina actually belong to C. pseudomacrostigma. A newly isolated Japanese strain of C. media was phylogenetically separated from "C media" SAG 10.87, which was further distinguished from C. media by the morphology of the stigma.