Phyllosiphon duini sp. nov. (Trebouxiophyceae, Chlorophyta), a Species Isolated from a Corticolous Phototrophic Biofilm

Abstract The Watanabea clade of the Trebouxiophyceae includes unicellular coccoid green microalgae that mostly thrive in subaerial microhabitats. Recently, a number of new genera and species were described on the basis of the DNA sequence data and morphological observations. The peculiar genus Phyllosiphon, which forms a monophyletic clade within the Watanabea clade, is characterized by forming siphonous parasitic stages thriving in the leaves of the Araceae. In addition, several previous studies demonstrated that members of the genus Phyllosiphon also include free-living chlorelloid individuals that occur on various subaerial substrates. A number of Phyllosiphon members sampled from European subaerial microhabitats have so far not been taxonomically described, because they were not available in cultures. In this study, we provide a taxonomic description of a new species of the genus Phyllosiphon, P. duini, isolated from a corticolous biofilm growing on Quercus pubescens in a sub-Mediterranean forest stan...