.332 A MANUAL OF THE PENICILLIA 



with prominent fascicles typically produced in marginal areas, heavily 

 sporing throughout, in light gray-green shades. 



Conidiophores simple or in fascicles, undulate or sinuate, smooth- walled, 

 up to 400 to 500/x or more in length. 



Penicilli asymmetric, variable in pattern, loosely divergent, often twice- 

 branched below the level of the metulae, with metulae comparatively 

 short and sterigmata unusually small and numerous in the verticil. 



Conidia thin-walled, smooth, elliptical to subglobose. 



Cultures usually producing a distinctive fragrant odor. 



The series is represented by a single variable species to which either of 

 two names might be properly applied, namel}^: Penicillium patulum Bainier 

 and P. urticae Bainier. The first of these species was inadequately de- 

 scribed, but fairly accurately illustrated in 1906. The second species was 

 described a year later in more detailed and precise terms, but obviously 

 approximated P. patulum. Cultures believed to represent types of both 

 species have been preserved and were included in the present study. No 

 significant differences were observed. Since Bainier 's description of P. ur- 

 ticae is more accurately draun, we prefer to recognize this rather than the 

 older name P. patulum. The general series is referred to under the same 

 designation. 



Members of the series are easily recognized by the characters listed 

 above. Especially diagnostic are the rather restricted, granular to fascic- 

 ulate colonies in gray -green to pale yellow-green shades; the loose rangy 

 character of the penicilli; and the crowded verticils of unusually small 

 sterigmata (fig. 136B). 



Wlien inoculated into sound citrus fruits, members of the series produce 

 black to dark bro^\^l necrotic areas 1.0 to 1.5 cm. in about 10 days, and 

 throughout the central area produce a pronounced purplish coloration, 

 but without marked evidence of tissue destruction. They can hardly be 

 regarded as parasitic. They are occasionally isolated from citrus or other 

 types of fruit, but typically appear to represent decay organisms that 

 may be expected to appear upon a variety of decomposing vegetable ma- 

 terial. 



All members of the series, apparently, produce an antibiotic, reported 

 in 1943 by Professor Raistrick and co-workers as "patulin," but later 

 sho\\Ti to be identical with claviformin, clavacin, etc. (see p. 537). 



Thom, in 1930, drew a distinction between Penicillium urticae Bainier 

 and P. patulum Bainier upon the basis of culture odors : Penicillium urticae 

 being reported as characterized by the production of a peculiar and dis- 

 tinctive ethereal odor, whereas P. patulum produced little or no odor. 

 Careful examination of many cultures with regard to this character has 



