264 



A MANUAL OF THE PENICILLIA 



in some strains remaining so, in others becoming light gray in G to 10 

 days from the development of abundant sclerotioid perithecia (fig. 70 A), 

 in still other strains (mostly long maintained in culture) developing peni- 



FiG. 70. Penicillium asperum (Shear) n. comb. A , Two-week old colonies of strain 

 NRRL 20S8 on Czapek agar. B, Penicillus as developed in strain XRRL 71.5, X 1300. 

 C, Low-power view of perithecia in NRRL 715 on corn meal agar, X 40. D, Asco- 

 spores from the same, X 1500; note furrowed ascospores marked by arrows and the 

 thick-walled cells (right and lower left) that comprise much of the sclerotioid peri- 

 thecium. 



cilli rather abundantly in marginal areas which appear velvety and show 

 gray shades near court or mineral gray (Ridgway, PI. XL VII); exudate 

 fairly abundant, clear, in small droplets; odor lacking or indefinite; re- 

 verse at first colorless, in age becoming dark brownish to fuscous in central 



