Phylogeny of the Hypochnicium punctulatum complex as inferred from ITS sequence data

Abstract

Parsimony analysis based on ITS sequence data was carried out to investigate the Hypochnicium punctulatum complex (Basidiomycota). The study gives full support to earlier, crossing test-based species delimitations. Altogether, 18 specimens were sequenced and their spore sizes plotted together with measurements from the corresponding type specimens. Spore sizes were found to cluster readily into four groups, all of which were supported by the phylogenetic analysis. However, in the case of H. punctulatum and H. albostramineum, the morphological delimitation is unsatisfactory and a zone of potential spore size overlap is shown to exist. The new combination Hypochnicium cremicolor is proposed for a species previously known as a small-spored taxon in the H. punctulatum complex, and H. caucasicum is shown to be a younger synonym to H. wakefieldiae. A key to the species is provided.