472 A MANUAL OF THE PENICILLIA 



under the same specific name by McCulloch and Thom, Science N.S, 

 67: 216-217. 1928. See also, McCulloch and Thom in Jour. Agr. 

 Res. 36: 217-224, PI. I. 1928; Thom, The Penicillia, pp. 381-383, 

 fig. 58. 1930. 



Colonies upon Czapek's solution agar differing in habit when grown at 

 different incubation temperatures: At temperatures above 25 °C., producing 

 abundant sclerotia with conidiophores generally few and inconspicuous; 

 at 15°C. or lower, showing abundant green conidial areas with delayed or 

 partially suppressed sclerotium formation. Upon Czapek's solution agar 

 at 24°C. producing somewhat restricted colonies consisting of a fairly 

 tough basal felt, with central area commonly raised and more or less 

 floccose, and with marginal area radially and irregularly furrowed (fig. 

 122A); sclerotia normally appearing about the fifth or sixth day and de- 

 veloping in successive concentric zones in some strains or as sectors or 

 localized areas in others, and giving the characteristic appearance of the 

 species, varying greatly in size, commonly 150 to 300m but sometimes up 

 to 550m in diameter, at first cream to light pinkish tan, in age becoming 

 tan or very pale brown, smooth, and composed of thick- walled cells 8 to 

 12m in diameter, retaining their vitality several months (fig. 122C); odor 

 none; drops of orange-yellow fluid often more or less conspicuous; reverse 

 at first uncolored or yellowish, eventually light pinkish cinnamon; conidio- 

 phores generally few, scattered, and inconspicuous among the sclerotia in 

 strains newly isolated, in older stock cultures more abundant and com- 

 monly arising from within the floccose felt, often very long (up to 2 mm.) 

 and about 3.0 to 3.6m in diameter, with walls more or less roughened, later 

 developing in more or less conspicuous tufts, fascicles, or complex branching 

 coremia in the center of the colony and definitely green (bluish gray-green) ; 

 penicilli usually consisting of the main axes of the conidiophores with or 

 without one or two branches (fig. 122D), 15 to 25m by 2.5 to 3.0m, bearing 

 few metulae 10 to 12m long; sterigmata 10 to 12m by 2.0 to 2.5m, ^vith 

 tapering rather than acute points, in verticils of 4 to 8; conidia subglobose 

 to elliptical, smooth, hyaline, 2.8 to 3.6m by 2.5 to 3.0m, often adhering in 

 long chains in fluid mounts, more or less parallel, tangled as seen in the 

 penicillus. 



Colonies on Czapek's solution agar when grown at 14° to 15°C. pro- 

 ducing abundant mycelium and conidial areas light dull glaucous blue, 

 glaucous blue, or greenish glaucous blue (Ridgway, PL XLII) to the very 

 margin of the colonies; sclerotium formation delayed and reduced, not 

 dominating the growth; conidiophores partly simple, partly aggregated 

 into coremia, tending to be longer and coarser, commonly 3m to 4.5m in 

 diameter, with walls pitted or roughened; penicilli coarser, more complexly 



