ASYMMETRICA-FASCICULATA 543^ 



generally not pronounced; reverse and agar becoming quickly colored in 

 rich 3'ellow-bro\vn shades, less commonly pinkish or reddish brown; peni- 

 cilli comparatively large, mostly 40 to 45/x in length, bearing conidia in 

 tangled chains up to 100/x or more in length, asymmetric, comparatively 

 regular in form, consisting of one or two appressed branches in addition 

 to the main axis; conidiophores variable in length from 100 to 200/x or 

 more at the margin up to 500 to 1,030m in the strongly fasciculate central 

 areas, 3.5 to 4.5/x in diameter, with walls closely and conspicuously rough- 

 ened; branches commonly 15 to 25m by 3.0 to 4.4^, occasionally rebranched; 

 metulae in groups of 4 to 6, measuring 12 to 16m by 3.0 to 4.0m \vith walls 

 of metulae and branches usually roughened like the conidiophores; sterig- 

 mata numerous, in crowded clusters of 6 to 10, mostly 9 to 12m by 2.0 to 

 2.5m with walls apparently smooth; conidia globose to subglobose, mostly 

 3.0 to 3.3m in diameter but ranging from 2.5 to 4.0m, with walls smooth. 



Colonies on steep agar spreading more rapidly, 6.0 to 7.0 cm. in 10 to 12 

 days with surface conspicuously granular but with fasciculation less clearly 

 evident than on Czapek, heavily sporing throughout, with color in conidial 

 areas as described above; exudate production less pronounced; colors in 

 colony reverse generally' in duller shades; penicilli as on Czapek but with 

 some conidia larger and slightly elliptical. 



Colonies on malt agar spreading broadly, attaining a diameter of 6.0 to 

 7.0 cm. in 8 to 10 days, plane except for limited floccose overgrowths in 

 colony centers, heavily sporing throughout, conspicuously fasciculate (fig. 

 139B), especially in marginal areas, conidiophores 1.0 to 1.5 mm. in length, 

 commonly appearing yellowish and with adherent orange to deep amber 

 drops; odor usually not pronounced ; penicilli as on Czapek but with conidio- 

 phores, branches, and metulae more coarsely roughened. 



Species description centered primarily upon strains NRRL 2032 received 

 in February 1946, from the Centraalbureau, as Penicillium corymbijcrum 

 Westling, isolated by them in 1941 from a green fly; and NRRL 999, iso- 

 lated by K. J. Kadow, University of Illinois Agricultural Experiment Sta- 

 tion in 1935, from horse radish roots, and diagnosed at that time by Thom 

 as approximating P. hirsutum Dierckx. 



Other strains duplicating the above have been isolated or received from 

 collaborators periodically but, when continued in laboratory culture, usu- 

 ally lose certain of their characteristic features within 5 to 10 years. 



Strain NRRL 996 (Thom No. 5034.64) was received in 1929 from Dr. 

 Birkinshaw, Nobel Explosives Co., Ardeer, Scotland, and was cited by 

 Thom in his Monograph (1930, pp. 424-425) as apparently representing 

 Westling's species. At that time, the culture was strongly fasciculate, 

 produced abundant drops in orange to deep red shades, and colony reverse 

 in deep orange, reddish orange or almost black shades. This culture still 

 produces penicilli characteristic of the species. Colonies, however, are 



