ASYMMETRICA-FASCICULATA 549 



fied by Thorn (1930). PeniciUium daviforme, as the name suggests, is 

 characterized by club-shaped coremia. In its typical aspect these are 

 cleariy differentiated into a compact, fibrous stalk 1 to 2 mm. or more in 

 length and 250 to 400m or more in diameter, terminated by an expanded 

 and typically rounded "sporehead" in which tremendous numbers of peni- 

 cilli become intimately interiaced to produce a continuous spore (conidium) 

 bearing surface. Chains of conidia, remaining parallel and adherent, de- 

 velop from this sterigmatic layer and tend to separate into broad columnar 

 masses as they increase in length, with the result that the mature spore- 

 heads commonly appear deeply and irregulariy dissected (fig. 140B). Not 

 infrequently conidial structures may be aggregated into palisade-like masses 

 rather than collected into the typical and separate coremia that character- 

 ize the species. When grown in one-sided illumination the coremia are 

 markedly phototropic, longer, and often spatulate rather than rounded. 

 In extreme cases they may become strongly dissected with conidial areas 

 limited to the outermost tips of the branching structures. Similar dis- 

 sected coremia often develop in marginal areas of aging colonies after two 

 or three weeks. 



PeniciUium clavigerum, as the species is regarded here, is believed to be 

 closely related to P. claviforme. Colonies normally present a strongly 

 coremiform aspect, conidiophores are smooth-walled and penicilli are large, 

 asymmetric, and usually branched. Unlike the coremia of P. claviforme, 

 which typically show a clear differentiation into sterile supportive stalks 

 and enlarged sporeheads, the coremia of P. clavigerum, are of looser texture 

 and are more nearly uniform in diameter throughout. Although conidial 

 heads are generally concentrated in the terminal portion of the coremia, 

 they may be borne over the greater portion of their entire length. The 

 coremia often appear more or less feathery and in some measure suggest 

 the structures seen in the P. granulatum series; they differ from these, how- 

 ever, in their greater length and more compact nature, and in being com- 

 posed of smooth rather than conspicuously rough-walled conidiophores. 



PeniciUium claviforme Bainier, in Bui. Soc. Mycol. France 21: 127, PI. XI, 

 figs. 8-11. 1905. Saccardo, Sylloge Fung. 18: 520. 1908. Thom, 

 U. S. Dept. of Agr., Bur. .\nim. Ind., Bui. 118, p. 44, fig. 10. 1910; 

 and The Penicillia, pp. 432-433, fig. 68. 1930 



Synonyms: Coremium claviforme (Bainier) Peck, in New York State 

 Museum Bui. 131, p. 16, 1909. 

 Coremium silvaticum Wehmer, in Ber. Deut. Bot. Ges. 31: 



373-384. 1914. 

 PeniciUium silvaticum (Wehmer) Biourge, in Monograph, 

 La Cellule 33: fasc. 1, p. 105. 1923. 



