658 A MANUAL OF THE PENICILLIA 



Inireau as Penicillium craterijonne 0. and A. (Dattilo-Rubbo's strain). 

 When examined by us, this same strain was diagnosed as approximating 

 P. ruhrum StoU (see p. 637). 



Penicillium herquei Series 

 Outsianding Characters 



Colonies deeply velvety to almost lanose, less commonly floccose; with 



vegetative hyphae usually in shades of yellow-green to bright green; 



conidia in dull yellow-green shades; reverse dark yellow-green to brown 



or almost black. 

 Conidiophores arising from the substratum or the basal felt, comparatively 



long and coarse, usually roughened, at least in the terminal area. 

 Penicilli typically biverticillate and usually symmetrical or nearly so, but 



with metulae comparatively coarse and often more or less divergent. 

 Sterigmata in large clusters, not characteristically lanceolate but tapered 



abruptly to narrow conidium-bearing tubes. 

 Sclerotium-like masses of heavy- walled, polygonal cells produced in some 



strains and species; black to dark brown, usually elongate, and often 



partially buried in the substratum. 



Series Key 



3. Vegetative mycelium typically in yellow-green shades; conidiophores long and 

 coarse, usually roughened; reverse dark but seldom developing true reds. 



P. herquei series 



a. Sclerotia lacking or rarely produced and limited in number; metulae numerous 



and somewhat divaricate; conidia elliptical. 

 1'. Conidiophores usually less than 1 mm. in length and 4.0 to 4.5^ in diameter. 



P. herquei Bainier and Sartory 



2'. Conidiophores commonly 1 mm. or more and up to 2 mm. in length by about 



8m in diameter P- olsoni Bainier and Sartory 



b. Sclerotia very abundant, characterizing the species; metulae 3 to 5 in number, 



in compact verticils; conidia globose P. novae-zeelandiae van Beyma 



Members of the series occur rather infrequently in almost all soils exam- 

 ined, and are occasionally isolated from decaying vegetation, fruits, exposed 

 tentage and fabrics, wood, and other organic materials undergoing slow 

 decomposition. They appear to be widely but not abundantly distributed 

 in nature. Once encountered, they are easily recognized, for the bright 

 yellow-green colors that characterize the vegetative mycelium, and usually 

 the colony reverse, are not encountered elsewhere in the genus Penicillium. 

 Conidial structures are also comparatively coarse and are not easily mis- 

 taken for those of other series either within or outside the Biverticillata- 

 Symmetrica. 



Three species are recognized, namely: Penicillium herquei Bainier and 



