408 A MANUAL 'OF THE PENICILLIA 



Colonies on Czapek's solution agar growing very restrietedly, attaining a 

 diameter of 1.5 to 2.0 cm. in 2 weeks at room temperature (fig. 107A), 

 heavily sporing, velvety to almost lanose, loose-textured, about 1 mm. deep, 

 often raised in central colony area, with marginal zone comparatively thin, 

 sometimes radially furrowed, azonate or narrowly zonate, in older colonies 

 commonly producing a yellowish zone of submerged growth extending 1-2 

 mm. beyond the margin of conidial development; aerial stolons occasionally 

 seen, comparatively short and stout; growing colonies with narrow marginal 

 zone white to cream in color, quickly shading to dull yellow-green near tea 

 green or vetiver green in conidial areas, approaching andover green in age 

 (Ridgway, PL XLVII) or in some strains deeper yellow-green; limited exu- 

 date produced mostly as small partially submerged droplets, dull yellow 

 to deep orange-brown in color; odor slight, not distinctive; reverse in dull 

 olive green to drab shades; conidial structures very abundant, borne in a 

 close stand, arising primarily from a basal mycelial felt at the agar surface; 

 conidiophores erect, usually straight and appearing more or less rigid, 

 mostly 300 to 500m in length, occasionally up to 700/1 by 4.0 to S.O/x with 

 terminal area commonly swollen, conspicuously septate, with walls com- 

 paratively heavy, smooth, or delicately roughened; penicilli compact, 

 irregularly branched with 1, 2, or more branches closely appressed, bearing 

 crowded clusters of metulae and sterigmata and tangled conidial chains 

 forming a loose, irregular mass 50 to 75m in length (fig. lOGAj); branches 

 mostly 10 to 17m by 4.0 to 4.5m, but commonly up to 6.5 to 7.0m in diameter; 

 metulae in groups of 3-6, enlarging upward, commonly wedge-shaped, 

 measuring 9 to 12m in length by 4.0 to 4.5m in diameter in a median plane, 

 commonly inflated measuring up to 6.0 to 7.0m in diameter (fig. IO6A2); 

 sterigmata usually 7.0 to 10.0m by 3.0 to 3.5m but often more or less inflated 

 and occasionally measuring up to 5.0 to 5.5m in diameter; conidia globose 

 to subglobose, variable, ranging from 3.0 to 4.5m, mostly 3.5 to 4.0m in diam- 

 eter, with walls slightly roughened. 



Colonies on steep agar restricted but growing somewhat more rapidly 

 than on Czapek, heavily sporing, about 1 mm. deep, essentially velvety 

 and marked by numerous shallow radial furrows; limited exudate, light 

 yellow-brown in color; penicilli essentially as on Czapek. 



Colonies on malt agar like the preceding, but with radial furrows less 

 strongly developed (fig. 107B), with marginal area more or less crenulate 

 in old cultures from the irregular development and proliferation of stolons; 

 penicilli as above but with conidiophore walls often more definitely rough- 

 ened. 



Species description based primarily upon culture NRRL 2011, received 

 from the Centraalbureau under this name in February 1946. The strain 

 had been received by them from Biourge in 1929 as Dierckx's species. It 



