298 A MANUAL OF THE PENICILLIA 



with submarginal zone becoming slightly gray with the very sparse de- 

 velopment of conidia, no exudate produced; odor almost lacking, slightly 

 sourish; reverse uncolored to cream; conidia generally borne upon single 

 sterigmata or upon very small clusters of sterigmatic cells, 8 to 12/i by 2.0 

 to 2.5m with abruptly narrowed apices, arising from aerial hyphae, rarely 

 from structures suggesting true penicilli, elliptical to subglobose, 3.0 to 

 3.5jLt by 2.5 to 3.0m, with coarse roughenings in spirally-arranged bands or 

 bars. 



Colonies on steep agar spreading more rapidly, attaining a diameter of 

 6.0 to 6.5 cm. in 12 days, closer textured and more conspicuously furrowed 

 than on Czapek but otherwise duplicating the preceding. 



Colonies on malt agar spreading broadly, up to 8.0 cm. in 12 days, 

 loose-textured, floccose, with surface growth showing a network of aerial 

 hyphae or thin ropes of hyphae, lightly sporulating with penicilli limited 

 in number and almost invariably monoverticillate. 



In Thom's Monograph (1930), PenicilHum daleae was placed in his 

 Asymmetrica-Funiculosa because of the tendency of colonies to show some 

 ropiness. Biourge had earlier placed it near to, or identical with, P. 

 janthinellum. Upon re-examination of Zaleski's description and illustra- 

 tions, and after re-study of the type strain, we regard the species as clearly 

 distinct from, but closely related to, P. janthinellum. The penicilli, even 

 at the time of original isolation, were much smaller than in forms such as 

 the P. terrestre series, and were apparently divaricate. The vegetative 

 hyphae are delicate, and colonies, on the whole, bear a much closer re- 

 semblance to the Divaricata than to the Funiculosa. 



The species, apparently, is not common in nature, since forms with its 

 peculiar pattern of conidial markings are rarely observed. The type 

 isolated by Zaleski from soil under pine near Poznan, Poland, is currently 

 maintained, in somewhat altered form, by the Centraalbureau and by the 

 Northern Regional Research Laboratory Collection as No. 2025. 



PenicilHum krzemieniewskii Zaleski (in Bui. Acad. Polonaise Sci.: Math, et Nat. 

 Ser. B, pp. 490-492; Taf . 56. 1927) was originally described in terms strongly sugges- 

 tive of P. daleae Zaleski, and conidia were illustrated with echinulations in winding 

 bands. This character was likewise emphasized by Thom in 1930, and is still clearly 

 evident in the culture studied by him and now retained by us as NRRL 922. A cul- 

 ture received from the Centraalbureau in May 1946, which presumably represents 

 Zaleski's type, has also been compared culturally and microscopically with P. daleae 

 (NRRL 2025) in the current study, and the two cultures are strikingly similar, differ- 

 ing primarily in the slightly heavier, but still sparse, production of conidia by P. 

 krzemieniewskii and the more delicate and more closely spaced roughening of its 

 conidia. The type strains of Zaleski's two species are not identical, but they do not 

 differ more than variant members of such well recognized species as P. roqueforti, 

 P. expansum, etc. Since Zaleski's types are believed to represent variants of a single 

 species, and since P. daleae is the more striking of the two forms, we feel that this 



