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.