A new chemotype of Buellia triseptata (Physciaceae)

Two collections of a chemically distinctive corticolous Buellia species were discovered in the herbarium of Sampaio at the University of Porto (po). A detailed morphological and chemical study of the specimens, as well as of additional material for comparison purposes, showed that they agree with Buellia triseptata, only differing by containing xanthones. They are here provisionally regarded as representing a new chemotype of B. triseptata. Further, the generic assignment of B. triseptata is discussed