Chapter XIV 

 THE ASPERGILLUS VERSICOLOR GROUP 



Outstanding Characters 



Conidial heads hemispherical to almost globose, in many different shades 



but usually showing green or blue-green. 

 Conidiophores smooth, colorless, more or less sinuous. 

 Vesicles globose to ovate or elliptical with radiate sterigmata borne over 



the upper half to three-fourths of the surface. 

 Sterigmata in two series. 

 Spores globose or subglobose, echinulate. 

 HiiHe cells found in occasional strains, globose. 



Members of the Aspergillus versicolor group are cosmopolitan in distribu- 

 tion. They occur regularly in soil, upon decaying vegetation, upon stored 

 grains, upon cured meats, and upon a multitude of other products exposed 

 to occasional moist air or undergoing slow decomposition. The morphology 

 of all strains (with the exception of Aspergillus j anus) is basically alike, but 

 different strains vary tremendously in their cultural appearance. This is 

 especially true of Aspergillus versicolor where conidial heads in different 

 strains vary in color from dark blue-green through green to yellow-green, 

 to yellow and orange, and finally in some strains to yellowish-cream, buff or 

 flesh color. 



Group Key 



I. Heads typically globose, less commonly hemispherical; blue-green in color with 

 the blue element dominant; colony reverse and substratum usually in red or 

 maroon shades A . sydowi series 



A. Conidial heads always blue-green, globose to radiate 



A. sydowi (Bain, and Sart.) Thorn and Church 



B. Conidial heads of two types: (a) blue-green in color, vesicles subglobose to 



elongate, borne on short conidiophores, and, (b) white, clavate, borne 

 upon long conidiophores A. janus Raper and Thom 



II. Heads hemispherical or nearly globose at times; in green shades without blue 

 admixture, buff to orange-yellow or occasionally flesh colored; colony reverse 

 usually in pink, yellow-red or purple-red shades, rarely almost colorless 



A. versicolor series 



A. Conidia echinulate A. versicolor (Vuill.) Tiraboschi 



B. Conidia smooth A. humicola Chad, and Sach. 



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