Infraspecific categories in fungi

The problems facing the mycologist centre on the difficulty of distinguishing between the individual and the population, the degree of host or substratum specialization and the limited range of morphological characters available for use as denning taxa. The use of the categories ‘variety’ and ‘forma specialis’ is considered, and examples are given of their application in the cereal rusts and in the genera Phoma and Fusarium. Micro-evolutionary trends in Auricula auricula are also considered and are used to illustrate how amenable fungi are to studies on speciation.