612 A MANUAL OF THE PENICILLIA 



near lily green becoming deep slate olive (R., PI. XL VI I) in age; exudate 

 limited; odor fairly pronounced, earthy; reverse in fairly bright reddish 

 brown shades, becoming walnut to deep brown in age; penicilli more con- 

 sistently symmetrical than on Czapek, with metulae and sterigmata ap- 

 pearing thinner and averaging more in the verticil, conidia more consistently 

 elliptical but otherwise the same. 



Colonies on malt agar growing rapidly, 5 to 6 cm. in 2 weeks, in some 

 strains consisting mostly of tufted sterile hyphae with limited conidial de- 

 velopment in more or less Avell defined zones and with conidial structures 

 arising mostly from the substratum, in other strains producing abundant 

 conidial structures in a velvety layer adjacent to the substratum through 

 which subsequently develop abundant and often crowded coremia up to 

 6 mm. or more in length (fig. 158B) that bear conidial heads over the upper 

 half and often appear somewhat feathery under low magnifications with 

 stalks definitely yellowish, commonly zonately arranged, odor lacldng or 

 indefinite; reverse in dull brown to drab shades; penicilli essentially as on 

 Czapek but commonly borne upon much longer conidiophores and showing 

 more numerous metulae and sterigmata. 



Species description centered upon Thom's notes on a strain (his No. 20) 

 received from the author, Georges Delacroix, Paris, but now lost from the 

 collection; NRRL 1030 received from the Thom Collection as his No. 

 4733.53, from Biourge in 1924; NRRL 1031, from J. W. Bowen, Johannes- 

 burg, South Africa, in 1938, as an unidentified culture; and a strain re- 

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

 species is also represented by NRRL 2020 received in January 1946, from 

 W. Lawrence White, Philadelphia Quartermaster Depot, as an unidentified 

 Penicillium isolated from deteriorating tentage in New Guinea; and by a 

 strain received from the Centraalbureau in February 1946, as P. clavigerum 

 Demelius, which had been isolated by them in 1939 from canvas. 



NRRL 1030 and the strain received from Baarn as Penicillium duclauxi 

 are derived from the same source and probably represent type material. 

 Thom received his cultiu'e (No. 4733.53) from Biourge, as the latter's No. 

 351. Biourge reported this as having been obtained from Dierckx who 

 had received it from Delacroix. The strain from Baarn was contributed 

 by Thom in 1938. 



This species, in its typical form, is clearly distinct, although it is ques- 

 tionable whether a sharp line of separation can be drawn between it and 

 Penicillium clavigerum Demelius, which we have placed in the Fasciculata 

 along with P. claviforme Bainier. The two species are placed in different 

 sections primarily upon the basis of the type of penicillus usually produced. 

 It should be noted, however, that some penicilli in P. clavigerum consist of 

 a single terminal verticil of metulae and strongly suggest the Biverticillata- 



