198 A MANUAL OF THE ASPERGILLI 



mon shades typical of the species. Among cultures currently under exami- 

 nation, this character is noted in an isolate from Argentine soil, is somewhat 

 more marked in NRRL No. 680 from Dr. G. A. Ledingham, Ottawa, 

 Canada, and is particularly striking in NRRL No. 1913 isolated by Dr. C 

 W. Emmons from Arizona soil. In all of these strains the basic morphology 

 is that of a typical A. terreus, hence Blochwitz's separation is reduced to 

 varietal rank. 



Aspergillus terreus var. floccosus Shih, in Lingnan Sci. Jour. 15 : 372, PI. 16, 



fig. 3, 1936. 



Strains characterized by deep floccose colonies in which conidial heads 

 are less abundant, develop late, and are borne almost entirely upon aerial 

 hyphae, are frequently encountered (fig. 58 B). While the conidial struc- 

 tures of certain of these strains appear entirely normal, in the majority of 

 isolates the heads are somewhat less compact and generally lighter in color. 

 This color difference is particularly marked among isolates from soils col- 

 lected in Texas, Central America, and Cuba with color commonly light 

 pinkish-cinnamon (Ridgway, PI. XXIX) to vinaceous-buff (PL XL) in age. 

 No sharp line of separation can be drawn between typical strains of A. 

 terreus and the floccose forms under consideration since isolates of interme- 

 diate character are encountered; nevertheless, these strongly floccose 

 cultures occur with sufficient frequency to warrant recognition of Shih's 

 varietal designation if his interpretation is somewhat broadened. The 

 variety is considered by the writers as a strongly floccose Aspergillus terreus 

 in which the head is commonly less compact and lighter in color, but with 

 the basic morphology of the conidial apparatus remaining that of the species 

 proper. This variety is represented by such strains as NRRL Nos. 1920 

 and 1921, isolated from Cuban soil contributed by Professor J. M. Osorio, 

 University of Havana; No. 1922, isolated from Texas soil, collected and sent 

 to us by Dr. F. E. Clark from Greenville, Texas. 



Other strains examined almost completely bridge the gap between the 

 pale colored strains of A. terreus var. floccosus and the light flesh colored 

 forms characteristic of Aspergillus carneus. 



Aspergillus terreus var. aureus n. var. 



This new and striking variety differs from the species in a number of par- 

 ticulars: colonies upon Czapek's solution and malt extract agars are com- 

 paratively slow growing, floccose, ranging up to 3 to 4 mm. deep, and are 

 bright golden yellow in color. Conidial structures are produced tardily and 

 in limited numbers. Conidiophores are appreciably longer than those of 

 the species, often becoming 500m or more in length, and bear columnar 

 heads, generally loose in texture, ranging in color from cream or light buff 



