ASYMMETRICA-DIVARICATA 291 



leaving it in the genus where it was assigned by Abbott, but to call atten- 

 tion to the probable relationshi|) of this form to Pemcillium lilacinum 

 Thorn. 



Spicaria violacea is a normal constituent of most soil floras. In dilu- 

 tion plates, upon such substrata as soil-extract-nitrate agar as used by 

 Smith and Humfeld (1930), it appears as floccose colonies, colored in violet 

 shades. In streak plates on hay-infusion agar (Raper, 1937), the vegeta- 

 tive mycelium remains submerged and the conidial structures usually 

 develop singly and appear as masses of loose, tangled chains of essentially 

 colorless conidia borne upon long and erect conidiophores. Not uncom- 

 monly, strains rapidly lose their capacity to produce conidia when main- 

 tained in laboratory culture. 



Penicillium humuli van Beyma, in Zentbl. f. Bakt. etc., (II) 99: 392-394, 



fig. 6. 1939. 



Colonies on Czapek's solution agar restricted, attaining a diameter of 

 2.0 to 2.5 cm. in 10 days at room temperature, extremely wrinkled and 

 buckled, especially in colony centers where the mycelial felt is often 

 cracked on upper surfaces of folds (fig. 79 A), thin, consisting of a tough 

 basal felt characterized by a closely interlaced surface growth of trailing 

 hyphae (described by van Beyma as "powdery"), light buff (Ridgway, 

 PI. XV) to pale pinkish buff (R., PI. XXIX) in color, azonate, no exudate 

 produced; no odor; reverse in the same shades as the colony, agar uncolored. 

 Penicilli may appear as monoverticillate structures borne on short conidio- 

 phores, 50 to 80m by 2.2 to 3.3m, that arise as branches from trailing hy- 

 phae, or more complex and often conspicuously divaricate structures that 

 may be irregularly branched but usually consist of a verticil of 2 to 3 

 terminal metulae and are borne on longer conidiophores up to 250/* in 

 length that typically arise from the basal felt (fig. 79C) ; metulae mostly 

 20 to 25m by 2.2 to 3.3m; sterigmata usually borne in clusters of 5 to 7, 

 mostly 10 to 15m by 2.5 to 3.5m (fig- 79D), producing loosely tangled chains 

 of conidia up to 60m long; conidia smooth, elliptical when first formed, then 

 subglobose to globose, mostly 3.0 to 4.0m in diameter but occasionally up 



to 4.5m. 



Colonies on steep agar growing more rapidly, attaining a diameter of 

 4.0 to 5.0 cm. in 10 days at room temperature, somewhat wrinkled in cen- 

 tral areas, radially furrowed, heavily sporing, superficially appearing 

 velvety but with conidial structures commonly arising as branches from 

 ascending hyphae in darker browTi shades near avellaneous (R., PI. XL), 

 slightly zonate; no exudate; no odor; reverse in avellaneous to fawn shades; 

 penicilli as on Czapek except monoverticillate forms less abundant, mostly 

 appearing as the more complex structures described above and with branch- 



