Penicillium and Related Genera

Abstract

Grouped in this chapter are genera which produce conidia in a structure termed a penicillus (Latin, little brush). A penicillus consists essentially of a well defined cluster of phialides or similar cells bearing small, single-celled, dry conidia in chains. The phialides are either attached to a stipe directly or through one or more stages of branching. Branches are of generally similar diameter to stipes (Fig. 7.1). This definition covers four genera here: Penicillium, Geosmithia, Paecilomyces and Scopulariopsis. Genera with greatly enlarged stipe apices, e.g. Aspergillus, are excluded, as are genera in which phialides are not borne in clusters or which produce wet, adherent conidia, e.g. Trichoderma.