Penicillium Link : Fries, Systema Mycologicum 3: 406. 1832. 

For synonyms click here

Vegetative mycelium abundant, entirely submerged or more or less effused, irregularly branching, septate, hyaline or brightly coloured and forming a dense and compact mycelia colony with well-defined  margins. Conidiophores borne from undifferentiated subsurface, superficial or aerial hyphae, rarely subapically proliferation under terminal penicillus. Stipes relatively narrow and thin walled, 2–5 μm, and in some species apically swollen, hyaline, in some species brown.  Conidial apparatus usually a well-defined structure (brush or broom), named the penicillus; penicilli comprised of phialides born directly on the stipe, or with one, two or rarely more verticils of metulae and rami as supporting cells. Conidiogenous cells phialides, borne in succession, i.e. not synchronous, rarely exceeding 15 μm in length, ampulliform, rarely cylindrical. Conidia in unbranched chains, borne basipetally, single celled, commonly between 2–5 μm in diameter, rarely exceeding 6 μm, en masse coloured in shades of green, rarely white, olive or brown. Chlamydospores absent. Sclerotia occasionally produced, composed of thick-walled cells, usually hard. Cleistothecia, if produced, usually hard, globose to subglobose, pseudoparenchymatous or sclerochymatous, ripening from the centre outward and often tardily; white, pale, yellow, orange or brown coloured, occasionally black or red. Asci ellipsoidal to globose, usually 8-spored, 5–15 μm. Ascospores lenticular, usually with equatorial ridges, 2–5 μm.

Notes on the generic diagnosis The concept of Penicillium of Raper & Thom (1949) is followed. In the concept of Houbraken & Samson (2011), Penicillium includes species with pigmented stipes (Thysanophora species, P. stolkiae and related species), as well as species formerly ascribed to the genera Eladia, Torulomyces, Chromocleista and Hemicarpenteles. The most dramatic changes in Penicillium are the incorporation of Eupenicillium and several other genera as synonyms (Houbraken & Samson 2011), and the transfer of species of the former Penicillium subgenus Biverticillium species to Talaromyces (Samson et al. 2011). Aspergillus paradoxus, A. crystallinus and A. malodoratus were shown to belong to Penicillium and were transferred in Visagie et al. (2014). Several species described as Penicillium belongs to other genera and not to Penicillium (see also Visagie et al., 2014 and Houbraken et al 2020).  The important difference between the current generic definition and Raper & Thom’ (1949) concept is the exclusion of Talaromyces and related Penicillium species. In our concept, only teleomorphs producing pseudoparenchymatous and sclerotioid ascomata are included (eupenicillium-type), and Talaromyces species, with soft ascomata without a well-defined, persistent wall, are excluded (Samson et al. 2011). Also the Penicillium species, which have lanceolate phialides and metulae with equal lengths as the phialides, are excluded. These species are also phylogenetically distinct and accommodated in Talaromyces.

List of accepted species in Penicillium

The following list includes species names that are accepted in the genus Penicillium. Even though the updating of the accepted species list began for nomenclatural purposes, we aim to make this list more functional by including additional information linked to the species names. The list thus includes MycoBank numbers where complete nomenclatural data can be obtained, collection numbers of ex-type strains for future taxonomists requiring authenticated reference material, the species current sectional classification, and GenBank accession numbers for ITS barcodes and, where available, alternative molecular identification markers for BenA, CaM and RPB2.

Despite the considerable amount of time and effort spent on completing this list, there is the possibility of errors or oversights. As such we solicit and gratefully accept any comments on missing names, errors or new data that has become available, especially when publishing a new species. We would also appreciate suggestions for making the list more useful.

When using information provided in this list, please cite Visagie et al. (2014) and Houbraken et al. (2020).