Chapter X 

 ASYMMETRICA 



Sub-section: LANATA 



In this section of the Asymmetrica, colonies show an aerial vegetative 

 mycelium consisting of a cottony, lanose or floccose mass, web or felt. 

 Conidiophores generally arise as branches from the aerial mycelium, less 

 commonly directly from the substratum. Conidial areas commonly ap- 

 pear centrally after the establishment of the definite aerial felt and progress 

 toward the marginal areas. In some species the characteristic aerial 

 felt diminishes toward the end of the growing period, leaving the margin 

 velvety. Penicilli are usually comparatively large and irregularly 

 branched, with metulae and sterigmata often arising at different levels 

 in the fruiting structure. Conidiophores are, as a rule, fairly coarse with 

 walls more or less roughened. Conidial chains usually form tangled rather 

 than columnar masses. 



Following Thom's :\Ionograph (1930), we have included a number of 

 species in the Lanata which Biourge placed in his Zonata, since we believe 

 that the floccose aerial felt as a character brings together more nearly 

 related species than the formation of zones in the colonies as Biourge 

 grew them. 



The lines used to separate the Lanata are admittedly arbitrary. In 

 fact the section merges insensibly into each of the other sections of the 

 Asjonmetrica, and forms are placed in one or the other upon the judgment 

 of the observer as to where they may be most easily identified. Species 

 that may be strongly floccose but which produce definitely divaricate 

 fruiting structures are placed in the Divaricata. Species which may 

 produce more or less flocculent colonies but which present an overall 

 velvety effect and which are unmistakably closely related to strictly 

 velvety species are included in the Velutina. Species predominantly 

 floccose, and w4th penicilli of the same general type as the Lanata, but 

 showing trailing or ascending bundles of hyphae are assigned to the Funic- 

 ulosa. Species in which conidiophores arise primarily from the sub- 

 stratum and collect into definite tufts or bundles are automatically 

 placed in the Fasciculata. 



The lines of demarcation between the Lanata and the Fasciculata, in 

 particular, are often difficult to establish; and there are reasons for be- 

 lieving that the entire Penicillium commune series, with the possible ex- 

 ception of P. lanosum West, (see p. 431), represents an assemblage of 

 forms in which fasciculation is lacking but which are morphologically and 



419 



