480 A MANUAL OF THE PENICILLIA 



sporing in marginal and submarginal areas, usually granular from fascicu- 

 late arrangement of conidiophores, less commonly almost velvety with 

 growing margin irregular, usually 1.0 to 1.5 mm. wide, white but quickly 

 becoming colored (see above) in pale sandy brown shades approximating 

 pinkish buff (Ridgway, PI. XXIX) with the ripening of conidia; exudate 

 usually limited, clear; odor moldy, not strong; reverse in orange-red shades, 

 ranging from vinaceous pink to cacao brown (R., PI. XXVIII); penicilli 

 comparatively large, mostly 35 to 50/i in length, but ranging from 25 to 

 60m and bearing tangled conidial chains up to 50^ or more in length, borne 

 upon conidiophores up to 500/x by 3.5 to 4.0^1 with walls finely roughened; 

 penicilli asymmetric, irregular in pattern, usually consisting of one or two 

 more or less appressed branches in addition to the main axis (fig. 123F); 

 branches mostly 15 to 20m by 2.8 to 3.3^, occasionally larger or smaller, 

 with walls finely roughened; metulae usually in clusters of 3 to 5, mostly 

 10 to 12m by 2.5 to 3.3iu, but ranging from 9 to 15/i in length; sterigmata 

 numbering about 5 in the verticil, 8 to 10/i by 2.5 to 2.8^; conidia elfiptical 

 when first formed, commonly becoming subglobose in age, 3.0 to 3.5^, 

 with walls smooth or very faintly roughened. 



Colonies on steep agar more rapidly growing than on Czapek, 5.0 to 

 5.5 cm. in 2 weeks (fig. 123E), but otherwise essentially as described above; 

 exudate abundantly produced, clear, collecting into conspicuous drops 

 along radial lines; odor pronounced, somewhat moldy; penicilli generally 

 as above but smaller and frequently appearing fragmented or under- 

 developed. 



Colonies on malt agar growing rapidly, 5.0 to 6.0 cm. in 2 weeks, loose- 

 textured, floccose, about 2 mm. deep, very light sporing, white to very 

 pale buff, showing a definite tendency to develop fasciculate hyphal 

 bundles (mostly sterile) at the margins; penicilli as on Czapek except very 

 conspicuously roughened even to the sterigmata, with central portions of 

 metulae and sterigmata commonly inflated. 



The type strain was isolated in 1939 from dried Kentish hops by George 

 Smith, London School of Hygiene and Tropical Medicine, and in the same 

 year was deposited in the Centraalbureau at Baarn. The above diagnosis 

 is based upon Smith's original description together with our own observa- 

 tions on his culture which was sent to us in February 1946 by the Cen- 

 traalbureau. The culture is maintained in our Collection as NRRL 

 2035. Insofar as we know, no additional isolations have been made. 



The exact relationships of this species remain in doubt. Possibly it 

 represents a color mutation from some species such as Penicillium corymbi- 

 ferum Westling. Irrespective of its true relationship, we believe that it 

 can be assigned to the series with P. ochraceum more satisfactorily than 

 elsewhere and separated upon the basis of conidial pigmentation. 



