MONOVERTICILLATA 197 



Series Key 



b. Colonies growing rather restrictedly upon most media, especially Czapck's solu- 

 tion agar P- implicatum series 



1'. Conidial areas light blue-green, colony reverse in bright orange-red or red 

 shades, conidia globose to subglobose, in parallel or divergent chains 



P. multicolor G.-M. and P. 

 2'. Conidial areas comniuuly deep blue-green, colony reverse in orange-brown or 

 maroon shades, conidia broadly elliptical, usually in compact columns 



P. implicatum Biourge 

 3'. Conidial areas yellow-green to gray-green, reverse in orange-red shades (ap- 

 proaching brick red), conidia strongly elliptical or pyriform 



P. sublateritium Biourge 



The Penicillium implicatum series represents an aggregation of strains, 

 not identical in details of structure or reactions, but having much in com- 

 mon and grading into one another sufficientl}^ to justify grouping them 

 together. Three species are recognized, namely: P. implicatum Biourge, 

 P. multicolor Grigorieva-Manoilova and Poradielova, and P. sublateritium 

 Biourge. 



Of these species, the first is by far the most abundant and the most 

 variable. Thom (1930, p. 211) recognized this variability by presenting a 

 series description covering Biourge's type and additional strains obviously 

 closely alhed to it. In the present discussion we have enlarged still fur- 

 ther the Penicillium implicatum series concept, with the characteristics 

 outlined above, and have incorporated into the specific diagnosis the 

 general range of characters formerly attributed to the series. The species 

 P. implicatum is characterized particularly by its restricted growth, 

 velvety surface, heavy spore (conidium) production, deep blue-green color, 

 and the development of deep orange-red to maroon shades in the colony 

 reverse and the surrounding medium. 



Penicillium sublateritium Biourge possesses the basic characteristics of 

 P. implicatum but differs from that species in developing colonies that 

 run to gray-green rather than blue-green shades and in producing rela- 

 tively large conidia up to 4.0 to 5.0m in long axis. 



Penicillium multicolor G.-M. and P. is clearly distinct and once studied 

 in culture is easily recognized. It is characterized particularly by the 

 production of j^ellow to orange or orange-red vegetative mycelium and 

 bright orange-red to scarlet shades in reverse. Unlike P. implicatum, 

 the pigmentation does not extend into the surrounding agar; conidia are 

 in lighter blue-green shades, and conidial chains, while mostly parallel, 

 are not adherent into definite columns. 



Members of this series occur regularly in and are fairly abundant upon 

 substrata subject to soil or dust borne contamination. Penicillium im- 

 plicatum is especially common. 



