274 A iVlANI^\L OF THE PENICILLIA 



c. C'()ni(li()i)liiirc wiiils smooth or nearly so. 



1'. White to pink sclcrotia reported P- rolfsii Thorn 



2'. Small masses of heavy-walled cells (as in P. i^nppi) produced in some strains. 



P. miczynskii Zaleski 



(see P. janthinellum series) 



2. Couidial areas commonly showing fasciculation, with conidiophores aggregated 



into more or less well defined bundles or tufts P. gladioli Machacek 



P. italicum Wehmer 

 (in the Fasciculata) 



This series is characterized particiUarly by the formation of true sclerotia 

 or sclerotia-hke masses of thick-walled cells, the production of biverticillate 

 and asymmetric penicilli, and a lack of any tendency toward fasciculation. 

 Four species are included, namely: Penicillium raistrickii Smith, P. pul- 

 villorum Turfitt, P. soppi Zaleski, and P. rolfsii Thom. Close genetic 

 relationship between these forms is not assumed, and the four species are 

 considered together principally as a matter of convenience. All produce 

 penicilli that typically consist of terminal verticils of rather divergent 

 metulae, hence are properly assignable to the Divaricata. 



The sclerotia, or sclerotia-like cellular masses, differ substantially in 

 the different species. In PeniciUium raistrickii these are mostly rounded, 

 very hard and gritty, naked or nearly so (fig. 73C), and withal bear a 

 striking resemblance to the flesh to pink colored sclerotia produced by 

 P. thotriii, in the Monoverticillata (fig. 44D). In P. pulvillorum the cellu- 

 lar masses are less regular in outline, often larger, firm but not stone-like, 

 and are commonly surrounded by a loose network of encrusted vegetative 

 hyphae which lends a golden yellow to brownish coloration to the colonies 

 on many substrata. The aggregates of heavy-walled sterile cells seen in 

 P. soppi (tig. 75) are unusual among the Penicillia. These small masses 

 suggest the beginnings of sclerotia, or possibly perithecia, but never de- 

 velop into the large masses of cells that usually characterize these struc- 

 tures. They are regularly produced adjacent to the substratum and are 

 generally obscured l)y an overgrowth of mycelium and abundant conidial 

 structures, being apparent, as a rule, only along the interface of adjacent 

 colonies. They seldom exceed GO to 70^ in diameter and in the authors' 

 experience seem to parallel the small aggregates of hiille cells produced in 

 Aspcri/illus granulosus Raper and Thom (1944). Exact identity of the 

 cellular elements in the two cases is not clawed, but the similarity in 

 appearance is most striking. Penicillium, rolfsii is included here primarily 

 because Thom (1910), in his original diagnosis, reported the production of 

 white to pink sclerotia ranging from elliptical to globose in form. 



None of the members of the series appear to be abundant in nature. 



Whereas the degree of relationship between the above forms and the 

 members of the ascosporic Carpenteles series is somewhat uncertain, the 



