MONOVERTICILLATA 159 



Not P. thomi Zaleski, in Bui. Acad. Polanaise Sci. : Math, et Nat. Ser. B, 

 492-493, Taf. 56. 1927. 



Colonies on Czapek's solution agar growing fairly rapidly in most strains, 

 attaining a diameter of 3.5 to 4.0 cm. in 10 to 12 days at room temperature, 

 occasionall}^ more restricted, conspicuously furrowed (fig. 44A), consisting 

 of a tough basal felt with surface appearing loose to slightly floccose, white 

 to pale blue-green, sporulating lightly throughout but more abundantly in 

 central colony areas and in localized sectors, in gray -green shades from court 

 gray to pea green (Ridgwaj^, PL XL^^II), sometimes producing abundant, 

 hard, rounded to oblong, pink sclerotia, up to 300 to 350^ in diameter 

 throughout the colony area (fig. 44D), sometimes in limited sectors only, 

 and often failing to develop sclerotia, especially in strains long maintained 

 in artificial culture; exudate clear, abundantly produced in some strains, 

 not in others; odor slight, suggesting mushrooms; reverse in pale yellow to 

 pinkish brown shades; penicilli strictly monoverticillate, bearing conidial 

 chains usually in loose columns up to ISO/x or more in length; conidiophores 

 arising from the basal felt and from interlacing aerial hyphae (fig. 44E), 

 seldom branched, with walls delicately echinulate (fig. 43A), variable in 

 length up to 300 to 400m by 3.0 to 3.5^, with apices enlarged, somewhat 

 vesicular about 4.0 to 5.0/u in diameter; sterigmata mostly parallel, in 

 crowded clusters, commonly 8 to 12 in the verticil, usually 8 to lO/z by 2.0 

 to 2.5/x, with conidium-bearing tips somewhat narrowed; conidia elliptical 

 to subglobose, mostly 3.0 to 3.5/x in long axis, smooth-walled (figs. 43A 

 and 44F). 



Colonies on steep agar spreading broadly, 5 to 6 cm. in 10 to 12 days at 

 room temperature, radially furrowed (fig. 44B), velvety in most strains but 

 with surface appearing loosely floccose in some, usually heavily sporing 

 throughout, in yellow-green shades near gnaphalium to pea green (R., 

 PI. XL VII), becoming dull gray shades in age; sclerotia as described above, 

 abundantly produced in some strains, not in others, developing adjacent 

 to the substratum, commonly obscured by overlying hyphae and conidial 

 structures, in other cases dominating the colony; penicilU as described 

 above. 



Colonies on malt agar spreading, not furrowed, somewhat less heavily 

 sporing, often showing more aerial mycelium (fig. 44C) ; commonly produc- 

 ing sclerotia more abundantly, in some strains forming a dense, continuous 

 layer adjacent to the substratum and lending to the colony an orange-pink 

 color interrupted only by areas of heavy conidial development; penicilli 

 as described on Czapek but with conidiophores more conspicuously and 

 closely echinulate. 



Species description centered upon NRRL 702, received from Ross W. 

 Davidson, Washington, D. C. in 1934, as an isolate from wood; NRRL 703, 



