Microfungi found on phellen of Jugulans nigra L. in Southeastern Ohio, USA

Abstract

Bark surfaces from black walnut (<em>Jugulans nigra</em>) trees of three sites in southeastern Ohio, half. Five. and ten miles from the Ohio River, were used in late autumn to isolate fungi in culture. as well as to search for the presence of fungal mycelium and spores. The pH of the cork also was determined. Fifty six, mostly cosmopolitan, species of microfungi and several yeasts were isolated, almost all belonging to imperfect form genera. with the largest number of species in the genus <em>Penicillium</em>. No relationship of fungal presence to cork pH was found among the sites whose acidity was related to closeness to the industrialized river edge. Relatively few fungi were isolated. and even fewer spores, and only four mycelia) growths were found by electron microscopy. Several spores seen could not be matched with fungi that had been isolated. The bark seems to be a trapping surface for spores. rather than a place of fungal growth.