Penname, a New Computer Key to Common Penicillium Species

Abstract

Problems in identifying Penicillium species are well recognised. Fundamentally, these result from a lack of completely stable characters of taxonomic value. Conventional dichotomous keys use a relatively few characters, and hence are sensitive to variation in them. The synoptic key is inherently more effective for this difficult genus, but the large number of species makes synoptic keys unwieldy to use. Designed to overcome this problem, Penname is a new computer based synoptic key to 68 common Penicillium, Eupenicillium and Talaromyces species. It is designed to be used with “A Laboratory Guide to Common Penicillium Species” (Pitt, 1988), but can be of value with other modern taxonomies as well. Penname is “user friendly”, accepting keyed in data on colony and microscopic characters directly on screen. Output in the current experimental version consists of a list of species, with the number of characters by which each differs from the test isolate. Later versions are intended to be “stand alone”, with simple taxonomic treatments of common species included.