250 A MANUAL OF THE PENICILLIA 



reported to have conidia elliptical to globose, about 3 by 2/i or globose 2/x 

 in diameter. It is thus possible that the latter more nearly approximated 

 PcniciUium cyaneum (B. and S.) Biourge. All of the above forms were 

 reported to have an optimum temperature of about 26-28°C., to liquefy 

 gelatine, to peptonize and coagulate milk, and to produce some citric acid 

 from glucose. 



Penicillium velutinum van Beyma, in Zentbl. f. Bakt., etc., (II) 91: 352- 



353, fig. G. 1935. 



Colonies on Czapek's solution agar fairly rapidly growing, attaining a 

 diameter of 4.5 to 5.0 cm. in 12 to 14 days, consisting of a tough basal 

 felt overlaid by a network of fine aerial hyphae producing an almost floc- 

 cose effect, central portions raised, about 3.0 to 4.0 mm. deep, remaining 

 almost white, irregularly buckled and wrinkled (fig. 68D), often splitting 

 in the center permitting growth and sporulation to occur on the under- 

 surface of the agar, marginal and submarginal zones somewhat thinner, 

 radially furrowed, light to heavy sporing after two weeks, almost velvety, 

 but showing abundant interlacing hyphae, in blue-green shades near green- 

 ish glaucous blue or bluish gray -green (Ridgway, PI. XLII), becoming 

 slate olive to deep slate olive (R., PI. XLVII) in age; no exudate produced; 

 odor lacking or indefinite; reverse in vinaceous orange shades from tilleul 

 buff to vinaceous buff or avellaneous (R., PI. XL) becoming sorghum brown 

 in age (R., PI. XXXIX); conidiophores commonly borne as branches from 

 aerial hyphae, occasionally directly from the substratum, mostly 50 to 

 IOOm long by 1.5 to 2.0/x in diameter, infrequently much longer, up to 250m, 

 with walls smooth; penicilli sometimes strictly monoverticillate, usually 

 ramigenous and irregularly branched, ranging from a terminal group of 

 metula-like branches to one, two, or more asymmetrically arranged mem- 

 bers, unequal in length, appearing independent and retaining their mono- 

 verticillate character, bearing conidial chains up to 100m in length, usually 

 tangled, sometimes loosely parallel; branches ranging from 5 to 20m or 

 more by 1.5 to 2.0m; sterigmata usually in simple verticils numbering 3 

 or 4 to 8 or 10, occasionally bearing secondary sterigmata, again occurring 

 singly, mostly G.O to 8.0m by 1 .5 to 2.0m, with tips somewhat pointed and 

 usually divergent; conidia globose or nearly so, about 2.5 to 3.0m, with 

 walls rough, echinulate, appearing dark olive green in mass. 



Colonies on steep agar spreading broadly, essentially as on Czapek but 

 with centers usually not as conspicuously raised, rather closely furrowed 

 in a radial pattern, broadly zonate, growing margin broad, white, almost 

 cottony, 4.0 to 5.0 mm., otherwise medium sporing throughout, in dull 

 gray-green shades near gnaphalium green (R., PI. XLVII), becoming dull 



