BIVERTICILLATA -SYMMETRICA 635 



rowed, heavily sporing throughout, colored in dull to deep dark yellow- 

 green shades often approaching slate olive in age (R., PL XLVII); conidio- 

 phores arising from the substratum or from trailing aerial hyphae that are 

 conspicuously encrusted and range from yellow to orange-red in color; 

 exudate generally lacking; odor indistinct; reverse in bright red shades 

 ranging from deep orange-red to deep purple-red ; details of conidial struc- 

 tures essentially as described above but with conidiophores, metulae, and 

 sterigmata measuring slightly larger and bearing adherent or somewhat 

 tangled chains of conidia up to 100/x in length. 



Colonies on malt extract agar usually about 3.0 to 3.5 cm. in 12 to 14 

 days (fig. 162B and F), in some strains broadly spreading up to 5.5 to 6.0 

 cm., heavily sporing except in marginal areas of some strains, in dull 

 yellow-green to deep olive shades, superficially appearing velvety but with 

 encrusted aerial hyphae always evident and occasionally prominent, conidio- 

 phores arising mainly from the substratum, up to 200/x in length and bear- 

 ing penicilli as described on Czapek but with conidial chains usually paral- 

 lel or adherent in poorly defined columns up to 200^ in length; exudate 

 lacking; odor pronounced, aromatic, suggestive of apples, in age sometimes 

 simulating black walnuts; reverse usually uncolored or in dull yellowish 

 brown shades. 



Species description centered upon NRRL 1061 from the Thom Collec- 

 tion as No. 4279C, received from Dr. K. Saito, Darien, Manchuria, in 1918; 

 duplicated also by NRRL 1136 isolated in 1940 from a mixed culture at 

 Arlington Farm, Virginia; NRRL 1214 isolated in 1941 as a "parasite" in 

 an Aspergillus niger culture used in a gluconic acid fermentation; NRRL 

 2019 received in April 1946, from the Philadelphia Quartermaster Depot, 

 as an isolate made in August 1944, from deteriorating tentage collected in 

 New Guinea; and numerous other strains essentially duplicating the above. 

 A strain received under this name from the Centraalbureau labelled 

 "NCTC, 1936" is probably correctly diagnosed but is somewhat atypical 

 in producing white to flesh-colored, floccose colonies that are non-sporulat- 

 ing at two weeks. Colonies in reverse show the deep red colors character- 

 istic of the species. A second strain received from the Centraalbureau 

 as this species and labelled "Baarn, 1943" is entirely typical. 



Certain individual cultures show outstanding strain characteristics, e.g.: 

 some show conidia smooth or nearly so (NRRL 1147), others grow more 

 rapidly and become almost floccose in marginal areas (NRRL 1059), others 

 are characterized by unusually strong apple-like odors (NRRL 2019), 

 while still others develop an abundant, yellow mycelium on malt agar 

 (NRRL 1749). These are but a few of many variations encoimtered. 



Penicillium purpurogenum regularly occurs in soil and decaying vege- 

 tation. It has been repeatedly isolated from moist paper stocks and starch 



