SUMMARY The genetic information of the authentic strain of Chlamydomonas kakosmos var. ovoidea has not been reported. In this study, the 18S‐ITS rDNA of the authentic strain SAG 26.87 was sequenced, and its taxonomic position was determined. The 18S‐ITS rDNA sequence of the strain SAG 26.87 was identical to the strain SAG 68.81, the authentic strain of Heterochlamydomonas callunae . Phylogenetic analysis based on 18S rDNA revealed that this strain belongs to Heterochlamydomonas . Light microscopy showed that this strain satisfies the diagnostic characteristics of Heterochlamydomonas , including two flagella arranged in parallel and of different lengths. In addition, the strain SAG 26.87 was morphologically indistinguishable from C. kakosmos var. kakosmos and H. callunae . Based on these results, Heterochlamydomonas kakosmos comb. nov. is proposed, and H. callunae is considered its synonym.
Matsuoka et al. (Fri,) studied this question.