240 



A MANUAL OF THE PENICILLIA 



2'. Conidial areas in blue-green shades with conidia elliptical and with 



ends somewhat pointed P. cyaneum (B. and S.) Biourge 



b. Conidia globose, ovate, or slightly elliptical and with walls roughened. 

 1'. Conidia globose or nearly so, in divergent chains, not forming columns 



P. ivaksmani Zaleski 

 2'. Conidia ovate to slightly elliptical, in parallel chains forming compact 



columns P- charlesii Smith 



2. Colonies growing more rapidly upon most media, usually 4.0 to 5.0 cm. diam- 

 eter or more in 10 to 12 days. 



a. Conidia rough, echinulate; colonics vinaccous to reddish brown in reverse. 



P. vclutinuyn v. Beyma 



b. Conidia smooth; colonies developing ycHow in reverse. P. citrinum series 



(see The Velutina pp. 338-354) 



This series inclucles a number of forms, first described and figured by 

 Bainier and Sartory (f912, f9f3) as species of Citromyccs, in which the 

 monoverticillate type of penicillus is characteristically produced, but in 

 which the fertile hyphae, instead of developing as erect conidiophores 

 tipped by single penicilli, usually appeared as creeping or ascending fertile 

 hyphae bearing branches from several septa. They vary in complexity 

 from simple penicilli to structures bearing verticils of fruiting cells (or 

 metulae) near the apices of the main axes (fig. 6GA and B). 



Cultures originally obtained from the Bainier collection under the names 

 published by Bainier and Sartory failed to comply with their descriptions 

 to such a degree that Thom (1930) questioned whether he had received 

 authentic cultures of any of them. Bainier and Sartory 's descriptions 

 appear to have been based upon colonies grown upon licorice sticks, hence 

 failed to include adequate data regarding colony characters. Thom's own 

 collections, and those of other investigators, however, showed that there 

 were in nature abundant forms which produced branching fertile hyphae, 

 with each branch terminating in a typical monoverticillate penicillus. 

 In his Monograph, Thom (1930) recognized these irregularly branched 

 forms as composing a separate and intermediate group, the Monoverti- 

 cillata-Ramigena, between the true monoverticillates, or the Monoverti- 

 cillata-Stricta, and the simpler biverticillate forms such as Penicillium 

 conjlophilum Dierckx and P. citrinum Thom. Some additional species 

 have been described since that time. Continued study has led us to re- 

 consider this arrangement, and we now believe that these forms should be 

 regarded as constituting a recognizable series within the true Monoverti- 

 cillata since they dffcr from the more usual forms principally in the rami- 

 genous character of their conidiophores. 



As understood by us, the series contains five well marked species, with 

 primary separation based upon the general rate and character of colony 



