Numerical Taxonomy of Species in the Genus Mallomonas (Chrysophyta) from China

Mallomonas is one of the biggest genera of Chrysophyta. In total, 37 species and 2 varieties have been recorded in China. Because of their narrow ecological optimum, species of this genus are considered as valuable bioindicators. However, taxonomy of Mallomonas remains unclear. We studied the numerical taxonomy of all the species and varieties recorded in China using Ward’s method and the furthest neighbor method based on 52 morphological characters. Shown in the phylogenetic trees, those species could be divided into two major clusters. One cluster includes 5 small clusters and another includes 2. The results of numerical taxonomy are partially consistent with the traditional ones with some divergences. Furthermore, the diversity of silicified scales including shapes and structures was confirmed as the most important character for identification of Mallomonas species.