STUDIES IN FOREST PATHOLOGY: VI. IDENTIFICATION OF CULTURES OF WOOD-ROTTING FUNGI

A numerical key for the identification of cultures of 126 species of wood-rotting fungi, with accompanying descriptions of the cultural characters of each species, is presented. The list of species includes many of the fungi most frequently encountered in studies of decay in various hosts, the species having been chosen without restriction as to host or locality. The descriptions and key have been based on cultural characters, both macroscopic and microscopic, that can be demonstrated readily without the aid of elaborate equipment or methods. Thus, cultures were grown in Petri dishes on Difco malt agar and on malt agar to which gallic or tannic acid had been added. They were incubated in the dark at room temperature and examined at weekly intervals for six weeks. Host relationships and physiological and morphological characters proved to be of diagnostic value. The physiological characters used in the key include the pigmentation of the mycelial mat, color changes induced in the agar by the fungus, rate of growth, and effect on media containing gallic or tannic acid. Morphological characters used in diagnosis were types and septation of hyphae, occurrence of secondary spores – chlamydospores, conidia, oidia – and of special structures, such as cystidia and setae, and the formation of fruit bodies. The numerical key will permit the interpolation of additional species as they are described and their code numbers prepared.