THE ASPERGILLUS VERSICOLOR GROUP 



185 



Pis. XIII and I) to almost black in some strains in age. Conidial heads 

 typically radiate to nearly globose (fig. 52 A), ranging from 100 to 150m, 

 but often reduced to small penicillate clusters of sterigmata especially in 

 marginal colony areas and upon aerial hyphae (fig. 52 B and C). Conidio- 



Fig. 53. Colony types in the Aspergillus versicolor group, on Czapek's solution 

 agar, 10 days, room temperature. A, Typical heavy sporing strain of A. sydowi. 

 B, Floccose, lighter sporing strain of the same species. C,A. versicolor, XRRLXo. 

 239, characterized by abundant green conidial heads and the production of deep 

 red exudate. D, A. versicolor, XRRL Xo. 227, characterized by flesh-colored conidial 

 heads. 



phores mostly arising from submerged hyphae, up to 500m in length by 5 

 to 8m in diameter, colorless, smooth, comparatively thick-walled. Vesicles 

 nearly globose, fertile over almost the entire surface, up to 20m in diameter. 

 Sterigmata in two series; primary 6 to l\x by 2 to 3m, secondary 7 to 10m by 

 2 to 2.5m- Conidia globose 2.5 to 3.0m (Bainier), in our culture up to 3.5m 

 in diameter, conspicuously spinulose, green en masse. Globose hulle cells 



