488 A MANUAL OP THE PENICILLIA 



zonate (fig. 12oD); penicilli definitely shorter and more compact than 

 upon the above media, with conidiophores consistently and conspicuously 

 roughened. 



Species description based upon XRRL 2028 received from the Centraal- 

 bureau in May 194(3, as Biourge's strain representing this species. Dupli- 

 cated essentially by XRRL 959 received by Thom from Biourge as his 

 type in 1924. This culture now produces colonies somewhat more loose- 

 textured than that received from J^aarn but is otherwise similar to it. 

 Strain NRRL 961, received from Carrera in Buenos Aires in 1940, is con- 

 sidered to be entirely' representative of the species as considered here. 

 Strain NRRL 962 (Thom's No. 3028) differs from the above in producing 

 colonies with young conidial areas in brighter yellow-green shades near 

 fluorite green (R., PI. XXXII), but with older conidial areas showing the 

 purplish vinaceous colors that characterize the species. Thom (1930) 

 considered the last mentioned strain as representative of the Penicillium 

 viridicatum series only, but the close sunilarity of this form to the type 

 material cited above leads us to the present more specific assignment. 



Penicillium palitans Westling, in Arkiv for Botanik 11: 53, 83-86, figs. 12 

 and 54. 1911. Thom, The Penicillia, pp. 396-397. 1930. 



Colonies on Czapek's solution agar attaining a diameter of 3.5 to 4.0 

 ^cm. in 12 to 14 days at room temperature, ranging from about 300 to 500^ 

 deep in marginal to submarginal areas up to 1 to 2 mm. in colony center, 

 surface appearing granular or mealy but generally not conspicuously fascic- 

 ulate, often narrowly zonate (fig. 125E]) with shallow to prominent radial 

 furrows, growing margin white, about 1 mm. wide, heavily sporing through- 

 out in most strains, at first in greenish glaucous shades through pistachio 

 green to shades of American green (Ridgway, PI. XL I) or Russian green 

 (R., PI. XLII) at maturity, becoming grayish olive in age (R., PI. XLVI); 

 often tending to develop limited areas of white sterile overgrowth ; exudate 

 clear or light amber, abimdantly produced in some strains, not in others; 

 odor pronounced, moldy; reverse colorless at first, through dull yellow 

 shades to pale brown and finally light purplish brown; penicilli asym- 

 metric, comparatively large, mostly' 40 to 50/x in length but ranging from 

 30 to 70m and bearing tangled, divergent, or loosely parallel conidial chains 

 up to 103m or more in length; conidiophores mosth' 100 to 200/x l>y 3.5 to 

 4.0/x in some strains, definitely longer in others up to 300 to 400m, with 

 walls roughened; penicilli generally showing I or 2 branches in addition 

 to the main axis, branches typicalh^ appressed and often unequal in the 

 same penicillus, commonly ranging from 15 to 25m or more by 3.0 to 3.5m; 

 bearing metulae in groups of 3 to 5, mostly 10 to 15m by 2.8 to 3.3m; sterig- 

 mata usually borne in compact verticils of 5 to 7, measuring 8 to 10m by 

 2.2 to 3.0m; conidia elliptical when first formed, then globose to subglobose, 



