198 A MANUAL OF THE PENICILLIA 



PennicilUuni multicolor appears twice in the Monoverticillata Key. 

 Cultural characteristics and details of structure place it in the P. iniplica- 

 tum series, but its tendency to grow rather rapidly upon steep agar and 

 other substrata containing vegetable extracts necessitates keying it with 

 the P. frequentans series also. 



Penicillium multicolor Grigorieva-Manoilova and Poradielova, in Archives 

 des Sciences Biologiques Leningrad 19: 117-131, fig. 1 and one plate 

 with photographs 1-6. 1915 (in Russian). Thorn, The Penicillia, 

 pp. 212-213. 1930. 



Colonies on Czapek's solution agar growing rather restrictedly, about 

 2.0 to 2.5 cm. in 8 to 10 days at room temperature, radially furrowed, 

 consisting of a comparatively thick felt 1.0 to 1.5 mm. deep (fig. 54A and 

 D), with basal portion close-textured and fairly tough, with surface loose- 

 textured, strictly velvety and heavy-sporing in some strains, in others 

 light sporing and almost floccose bui presenting a velvety appearance, or 

 showing both in the same culture, with growing margin 1 to 2 mm. wide, 

 pale yellow to rich orange in color, conidial areas developing in localized 

 central to sub-central patches against a backgi 3und of yellow to orange 

 or orange-red vegetative mycelium (appearing studded with orange to 

 orange-red granules when viewed under low magnification) in some strains, 

 in others heavily sporing throughout with the massed conidial structures 

 characterizing the colony, in blue-green shades near greenish glaucous 

 blue to deep bluish gray -green (Ridgway, PI. XLII); exudate limited to 

 abundant, yellow to pale orange; odor not pronounced, suggesting mush- 

 rooms; reverse in bright orange-red shades near flame scarlet or mars 

 orange to burnt sienna (R., PL II); conidiophores abundalntly produced 

 in some strains, sparingly in others, arising mostly from the substratum 

 (fig. 54E) but sometimes from aerial hyphae, usually unbranched, varying 

 in length from comparatively short up to 300 to 400ju by 2.0 to 2.5/i, ap- 

 parently smooth-walled in some strains, granular in others, or showing 

 both conditions in the same strain, walls sometimes studded with orange 

 colored crystals when viewed dry, apices slightly enlarged or in some 

 strains definitely vesicular up to 5.0 or 5.5^; penicilli strictly monoverti- 

 cillate consisting of compact terminal clusters of sterigmata, usually 6 

 to 10 or 12 in the verticil (fig. 54F), in some strains more, mostly 8 to lO/i 

 by 2.0ju with apices parallel or divergent, bearing chains of conidia up to 

 lOO/i long, loosely parallel but not producing definite columns; conidia 

 globose to subglobose, about 2.0 to 2.5ju in diameter with walls appearing 

 finely roughened. 



Colonies on steep agar growing more rapidly than on Czapek, up to 

 4.5 to 5.0 cm. in 10 to 12 days, radially furrowed (fig. 54B), texture as 

 described above, with margin usually broad, yellow to orange-red in color, 



