The taxonomy of the important mycotoxigenic species Penicillium viridicatum and P. verrucosum was reviewed to clarify disagreements relating to the three P. viridicatum groups erected by Ciegler and coworkers (A. Ciegler, D. I. Fennell, G. A. Sansing, R. W. Detroy, and G. A. Bennett, Appl. Microbiol. 26:271-278, 1973) and the mycotoxins produced by them. Cultures derived from the types of these...