Studies on Argentine Phylacia species (Hypoxylaceae) using a polythetic taxonomic approach

Abstract

The current study is dedicated to the taxonomy of the genus Phylacia (Hypoxylaceae) in Argentina. Fieldwork in the north of the country provided several fresh collections that were studied, using a polyphasic approach. The secondary metabolite profiles of the specimens were generated by high-performance liquid chromatography hyphenated by diode array and mass spectrometry (HPLC?DAD/MS) of the stromata. This study confirmed the presence of secondary metabolites that are also found in the related genus Daldinia. The detection of binapththalene tetrol (BNT), daldinal B, and daldinol, which are also characteristic of certain species of Daldinia and Hypoxylon, further confirmed the chemotaxonomic affinities within the Hypoxylaceae. The phylogenetic affinities of several species were determined using a multi-gene genealogy based on ITS, LSU, TUB2, and RPB2 sequences, confirming that Phylacia is most closely related to Daldinia, Rhopalostroma, and Thamnomyces. The new species P. lobulata, which features a rather unique stromatal morphology and seems to exhibit apparent host specificity for the endemic tree Pseudobombax argentinum, is described.