Decussiphycus sinensis sp. nov. (Bacillariophyceae, Mastogloiales) – a new species described from China, with comments on phylogenetic position of the genus

During the study of freshwater diatom communities in Hainan Province, China, we uncovered an unknown diatom species of the genus <i>Decussiphycus</i>, which is described as <i>Decussiphycussinensis</i> <b>sp. nov.</b> herein. The description is based on LM and SEM investigations; morphologically, the new species is compared to other taxa belonging to the genus. We complemented the description with the results of a molecular analysis based on SSU rDNA and <i>rbc</i>L sequencing. Molecular data is acquired for <i>Decussiphycus</i> for the first time. Hereby, we discuss the phylogenetic relationships between this genus and its closest allies - <i>Aneumastus</i> and <i>Mastogloia</i>, demonstrating the affinity of <i>Decussiphycus</i> within the order Mastogloiales.