XVI International Botanical Congess

In traditional literature, microscopic and substratum characteristics have delineated four morphospecies of Melanotus in the Andean-Patagonian forests of Argentina and Chile. We have made collections of Melanotus growing on Nothofagus spp., Chusquea and Aristotelia and found all collections to be micromorphologically indistinguish-able and sexually intercompatible. Previous work on isolates of Melanotus obtained from collections made in Europe, the North Coast of California, and Washington appear to belong to the same biological species as the Argentine isolates. With the exception of a putative cryptic taxon within the Argentine isolates, all specimens are tentatively referred to M. horizontalis.