260 A MANUAL OF THE PENICILLIA 



b. Ripe conidia typically in dull gray shades (scarcely showing any 

 green) such as steel gray to dark olive gray (Ridgway), globose; 

 colony reverse usually in yellow to deep orange shades 



P. nigricans series 323 

 1'. Conidiophore walls smooth or nearly so on all substrata. 



aa. Conidia strongly echinulate with conspicuous color bars. 

 1". Colonies heavily sporing, dull to dark gray in color 



P. nigricans (Bainier) Thorn 325 

 2". Colonies floccose, light sporing, white or nearly so 



P. albidum Sopp 329 



bb. Conidia delicately echinulate P. kapuscinskii Zaleski 330 



2'. Conidiophore walls coarsely roughened, at least on malt agar. 



aa. Conidia conspicuously echinulate P. melinii Thorn 331 



bb. Conidia smooth or nearly so P. raciborskii Zaleski 333 



2. Penicilli with divaricate character evident, but tending toward com- 

 pactly biverticillate with metulae usually borne at a single level and 

 conidia producing compact columns that are typically divergent 



P. citrinum series 

 (see The Velutina) 



Carpenteles Series 

 Outstanding Characters 



Perithecia characteristically produced, at first parenchymatous through- 

 out, often becoming sclerotioid, ripening from the center outward and 

 often late, in some species and strains not developing asci and ascospore 

 for 4 to 6 weeks or more, with some structures apparently remaining 

 sclerotioid indefinitely. 



Asci borne in chains or singly as branches from ascogenous hyphae, 8- 

 spored; ascospores lenticular, with convex walls smooth to conspicuously 

 roughened, showing equatorial areas well marked, with definite furrows 

 and ridges usually apparent. 



Colonies of most strains growing fairly rapidly upon most substrata but 

 often restricted on Czapek, characteristically developing abundant 

 perithecia adjacent to the substratum with surface commonly appear- 

 ing granular, perithecia sometimes massed and characterizing the colony; 

 conidial structures usually limited in number and generally not affect- 

 ing the colony appearance. 



Penicilli typically biverticillate and asymmetric but with monoverticillate 

 structures regularly present in limited numbers, sparsely produced in 

 some strains, more abundantly in others, usually borne on compara- 

 tively long, smooth-walled conidiophores arising mostly from the sub- 

 stratum. 



Series Key 

 (See General Key to Divaricata) 

 The so-called Carpenteles series embraces a limited number of ascosporic 



Penicillia of somewhat uncertain relationship, but of considerable interest 



