19G A MANUAL OF THE PENICILLIA 



broadened sufficiently to include it. Strains showing progressive grada- 

 tion between the P. frequentans and the P. lividum series have been ex- 

 amined. Representative of such strains is a soil culture received from the 

 Centraalbureau in June 1946, as the type of P. mucosuvi Stapp and Bortels. 

 The latter species is regarded as belonging with P. spimdosum (see p. 184). 

 The conidia of NRRL 731 are typically broadly elliptical, although, in 

 some cultivations, many appear subglobose. Some difficulty may be 

 experienced in locating the species in the Penicillium lividum series for 

 this reason. It is hoped that the examination of additional closely related 

 strains will, in time, enable us to establish the true relationships of P. 

 trzebinskii. 



Occurrence and Significance 



Penicillium lividum Westhng and allied species occur rather infrequently 

 among soil isolates but are believed to be widely distributed. Their role 

 in decomposition processes is unknown but is regarded as probably in- 

 significant. Bouriquet (1941) isolated P. lividum, P. rugidosum, Asper- 

 gillus niger, and a new species, P. vanillae, from vanilla undergoing spoil- 

 age in Madagascar. Mold damage was most prevalent at the base of 

 the fruits, an area relatively poor in vanillin. Growth of each of the above 

 molds was checked by a concentration of 1 percent vanillin when added to 

 a nutrient solution. Stapp and Bortels (1935) reported P. roseo-viridum 

 to break down tannin in concentrations of 5 to 50 percent. 



Penicillium implicatum Series 

 Outstanding Characters 



Colonies growing restrictedly upon most substrata, usually compact, 

 velvety, heavy sporing, mostly in blue-green shades; vegetative myce- 

 lium sometimes encrusted and pigmented, characteristically producing 

 conspicuous orange-red to maroon colors in colony reverse. 



Penicilli strictly monoverticillate, usually borne upon conidiophores arising 

 from the substratum or from a compact basal felt, erect, seldom 

 branched, variable in length, commonly less than 200m, but in some 

 strains 300 to 400/x, with apices usually inflated and appearing some- 

 what vesicular. 



Chains of conidia long, loosely parallel or adherent, often forming fairly 

 well developed columns, crowded in most strains and often tending to 

 break away as crusts in old cultures. 



Conidia smooth or delicately roughened, elliptical to subglobose or even 

 globose, from 2.0 to 2.5/x in some strains to 4.0 or S.O/i in others. 



