ASYMMETRICA-DIVARICATA 325 



recognition of the following species: (1) P. albidum, to include forms with 

 conidial structures and conidia essentially as in P. nigricans, but with 

 colonies persistently white or nearly so; (2) P. kapuscinskii, to include 

 forms with the general characters of P. nigricans, but with conidial areas 

 less darkly colored, reverse in pale orange shades, and conidia less con- 

 spicuously roughened; (3) P. melinii, to include forms with conidiophores 

 conspicuously roughened and penicilli commonly monoverticillate, but 

 developing typical divaricate structures in sufficient numbers to necessitate 

 placing the species here; (4) P. raciborskii, to include forms showing the 

 general characteristics of the group but producing smooth conidia upon 

 conidial structures with all walls conspicuously roughened. 



Penicillium nigricans (Bainier) Thom, in The Penicillia, pp. 351-353, 



fig. 56. 1930. 

 Synonym: Penicillium echinatum Dale, in Biourge's ^lonogr., La 

 Cellule 33: fasc. 1, p. 278, Col. PI. XI, and PL XVIII, 

 fig. 104. 1923. Discussed without name as C3 by Dale 

 in Ann. Glycol. 12: 42, PL III, figs. 51 and 52. 1914; 

 and named by her in Ann. Mycol. 24: 137. 1926. 



Colonies upon Czapek's solution agar (Col. PL V) growing rather re- 

 strictedly, 2.5 to 3.0 cm. in 10 to 12 days at room temperature, forming a 

 close-textured, fairly deep felt of delicate trailing hyphae and occasionally, 

 but not regularly, bundles or ropes of hyphae, plane or increasingly 

 wrinkled at higher temperatures toward 30°C., azonate at first, then more 

 or less zonate at margin (fig. 88A) ; conidial areas in various shades of gray, 

 steel gray, dark olive-gray, and Hathi gray (Ridgway, Pis. LI and LII), 

 in age becoming mouse gray with little or no trace of green; reverse yellow 

 to deep orange to deep ferruginous shades at various ages and under vary- 

 ing conditions; odor strong, suggesting certain species of Actinomyces; 

 drops abundant, colorless or slightly yellowish; conidia-bearing hyphae 

 variously short branches of aerial hyphae, or whole trailing hyphae show- 

 ing thickened walls and bearing short branches with penicilli, or as separate 

 conidiophores arising directly from submerged hyphae in marginal areas 

 (figs. 87A and 88C); penicilli terminal on trailing hyphae or on short 

 branches about 50m long, consisting of variously diverging branchlets 

 bearing few to many sterigmata and chains of conidia occasionally parallel 

 but usually divergent or tangled in age, with individual chains commonly 

 up to 50 to 75m in length; conidiophores variable in length as indicated 

 above, often very short, rarely more than 200m in length by 2.5 to S.Om, 

 with walls smooth but appearing internally granular; metulae strongly 

 divergent, variable, about 8 to 12/x by 2.0 to 2.5m ^vith apices commonly 

 inflated, each typically supporting a compact verticil of sterigmata simu- 



