636 A MANUAL OF THE PENICILLIA 



paste where it develops as dark green, powdery masses, surrounded by 

 areas of bright red color. It commonly occurs upon exposed tentage and 

 canvas, causing a marked discoloration of the fabric and sometimes pro- 

 ducing a marked reduction in serviceability. 



The following species are regarded as duplicating Penicillium purpuro- 

 genum Stoll: 



Penicillium sanguineum Sopp (Monogr., pp. 175-176; Taf. XIX, fig. 138, Taf. XXIII, 

 fig. 24. 1912) is believed to have been correctly assigned by Thorn (1930) to the P. 

 ■pur-purogenurn series. Re-examination of the original description and of Thorn's 

 notes on his culture, No. 4917.7 (now maintained as XRRL 1749), together with com- 

 parative study of this strain in culture, fails to show adequate bases for continued 

 recognition of the species. Undoubtedly, Sopp was working with some member of 

 the P. purpurogenum series but closer identification is impossible. 



Penicillium purpurogenum Fleroff -Stoll, was discussed in Biourge's Monograph 

 (La Cellule 33: fasc 1, pp. 235-237; Col. PL VII and PI. XI, fig. 66. 1923) in terms 

 which made impossible its separation from P. purpurogenum Stoll. Biourge's strain 

 when studied in laboratory cultures confirmed this relationship. 



Penicillium sulfureum Sopp (Monogr. pp. 172-173, Taf. XVII, fig. 120; Taf. XXIII' 

 fig. 22. 1912) was included by Thorn (1930) in his "P. luteum series — non-ascosporic." 

 The production of red to blood red colors in the substratum as noted by Sopp, seems 

 to align it with some member of the P. purpurogenum series. The isolate upon which 

 the species was based probably represented some strain of P. purpurogenum or P. 

 rubrum which was characterized by abundant yellow mycelium upon the particular 

 substratum employed. More exact placement cannot be made. 



Penicillium purpurogenum Stoll var. rubri-sclerotimn Thom, in Mycologia 

 7: 141-142, fig. 1. 1915; The Penicilha, p. 479. 1930. 



Thom established this variety to include certain strains producing a 

 cultural picture which he regarded as Penicillium. purpurogenum Stoll, but 

 which characteristically produced dark red to reddish brown sclerotia, at 

 least when newly isolated. His culture, No. 2670, isolated in 1912 by Dr. 

 Erwin F. Smith, was found by May, Herrick, and co-workers (1927, 1928, 

 1929) to produce gluconic acid and has been widely cited in biochemical 

 literature in connection with this fermentation. This strain originally 

 produced abundant sclerotia, but during the long period of subsequent 

 laboratory cultivation it has completely lost its capacity to produce these, 

 and it no longer develops the red colors which are typical of both the species 

 and the variety. The culture, now maintained as NRRL 1064, produces 

 light-sporulating, somewhat funiculose colonies in pale blue-green shades. 

 Superficially there is little to suggest the original isolate, but penicilli are 

 typically biverticillate and synmaetrical and show sterigmata and conidia 

 as in the original culture. 



