ASYMMETKICA-DIVARICATA 285 



ently intermediate between these two species are so commonly encountered 

 that S. violacea is included here, although described in another genus. 

 Transfer of Abbott's species to the genus Penicillium has been considered 

 but rejected since the conidial structures are so very variable in form, are 

 in fact as often Verticilliuni-V\k.e as penicillate, and usually show very 

 long, tapered sterigmata that are often extremely divaricate. If the genus 

 Spicaria is valid, then it would seem that this species should remain as- 

 signed to it. There is the further possibility that P. lilacinum Thorn 

 properly belongs in Spicaria, although we feel its Penicillium-like charac- 

 teristics justify its inclusion in any treatment of the genus Penicillium.. 



Penicillium lilacinum Thom, in U. S. Dept. Agr., Bur. Anim. Ind., Bui. 



118, 73-75, fig. 30. 1910. See also, Thom, The Penicillia, 



pp. 331-334, figs. 49 and 50. 1930. 



Colonies on Czapek's solution agar attaining a diameter of 3.0 cm. in 

 10 days at room temperature, floccose, loose-textured, commonly 1 to 2 

 mm. deep (fig. 77 A), with central colony areas raised in some strains, not 

 in others, irregularly showing few, shallow, radial furrows, azonate, at 

 first white, gradually developing lilac to vinaceous shades near grayish 

 vinaceous to purplish vinaceous (Ridgway, PI. XXXIX) with the produc- 

 tion and ripening of conidia, sporulation varying in different strains and 

 often diminishing with continued laboratory cultivation, generally abun- 

 dant; limited exudate produced, uncolored to vinaceous; odor slight or 

 lacking; reverse at first uncolored, later usually showing vinaceous shades, 

 and in some strains becoming strongl}^ colored near daphne red to ver- 

 nonia purple (R., PI. XXXVIII); conidiophores varying greatly in di- 

 mensions (fig. 76), arising from the substratum at the colony margin (fig. 

 7GBi) and from aerial hyphae in central colony areas, the former ranging 

 up to 500 or GOOyu or more in length by 3.0 to 4.0/i wide, the latter ranging 

 from very short, where the penicillus appears to arise almost directly from 

 the supporting aerial hyphae (fig. 76B2), up to 100 to 200/i by about 3.0m, 

 with walls smooth or appearing finely roughened (fig. 76B3), colorless or 

 in larger structures slightly yellowed; penicilli varying in size and com- 

 plexity (fig. 76A), bearing tangled chains of conidia up to 50 to 75/x in 

 length, not branched in the usual manner for the genus, in larger struc- 

 tures typically consisting of complete or partial whorls of metulae (or in 

 largest structures of branches bearing metulae) arising at two or more 

 levels (nodes) below the terminal clusters (fig. 76), up to 50^ or more in 

 length, in smaller structures commonly consisting of a single verticil of 

 metulae; metulae short, usually 5.0 or (i.O/i, occasionally S.O^t in length by 

 2.5 to 3.0)Lt; sterigmata mostly 5.0 to G.Oju in length abruptly tapering to a 

 comparatively long, thin spore-bearing tube approximately l.O/x indiam- 



