Abstract
We describe three new fungicolous species on the basis of phenotypic and phylogenetic differences from known species. Penicillium thiersii, P. angulare and Penicillium decaturense are described. Penicillium thiersii phenotypically is identified on the basis of several characteristics including growth rates, vesicle size and condium shape and roughening. Penicillium angulare is related most closely to P. adametzioides but differs from it by restricted growth rates and conidiophores greater than 60 μm in length. Penicillium decaturense is related most closely to P. miczynskii but differs from that species by growth rate, minimum growth temperature and pigment production on MEA. Multilocus phylogenetic analysis confirmed the genetic distinctiveness of P. decaturense and the closely related species P. miczynskii, P. chrzaszczii and P. manginii. Penicillium rivolii is a synonym of P. waksmanii on the basis of this analysis. Analysis of the EF-1α gene shows rapid changes of position, number and length of introns between the species, suggesting a recent evolutionary origin for the introns.
We are grateful to the late Dr Harry D. Thiers for collecting the fungal sporocarps, from which these cultures of Penicillium were isolated, while participating in the ARS Volunteer Program (1995–97). Bruce W. Horn helped with field collections in Georgia. Michael Hertwig translated the diagnoses into Latin.