Chapter XV 



GLIOCLADIUM, PAECILOMYCES, AND 

 SCOPULARIOPSIS 



Link, in 1809, described the conidial apparatus of Penicillium as arising 

 from septate branching mycelial hyphae as follows: "fertilibus erectis apice 

 penicillato," or roughly translated, as erect hyphae with apex branched to 

 form a little brush or broom. Saccardo, in the Sylloge (IV, p. 78, 1886) 

 inserted before "fertilibus" the following, "inaequaliter verticillato-ramu- 

 losae." This enlargement would include any fruiting branch that one 

 could call, loosely, a brush or broom as seen with magnification. Link, in 

 1816, described Penicillium roseum which is now regarded as a Gliocladium, 

 and certain species now known to belong in Cladosporium were also brought 

 in. Saccardo, as t.893 in his Fungi Italici (1877-1886), introduced Peni- 

 cillium brevicaule, which subsequently was used as the type species of the 

 genus Scopulariopsis. Thom, in 1910, described P. divaricatum, now as- 

 signed to Bainier's genus Paecilomyces. 



By the time Thom published his Monograph in 1930 sufficient informa- 

 tion was available and enough cultural material was at hand to attempt an 

 evaluation of the genera Gliocladium, Paecilomyces, and Scopulariopsis. 

 Each was regarded as distinct from Penicillium and from each other. Yet 

 all were regarded as more or less related. In all of these genera, the funda- 

 mental morphological unit is the conidium-bearing cell, the sterigma of 

 most authors, or the phialid of Vuillemin. This cell cuts off asexual aerial 

 spores, or conidia, from its apex successively, i.e., always with the newest 

 spore attached directly to the sterigma and the oldest at the outer end of 

 the unbranched chain. This eliminates all forms such as Cladosporium 

 with branching chains in which the youngest spore is at the tip of each 

 chain. 



Among these molds, which are often mistaken for Penicillia, are three 

 well defined groups. Of these, Gliocladium is believed to be probably most 

 closely related, although no ascosporic stage has been available for study. 

 The other genera, Paecilomyces and Scopulariopsis are believed to be further 

 removed genetically. Based upon the character of the ascosporic struc- 

 tures produced, one can reasonably assume that Paecilomyces is more 

 primitive, and Scopulariopsis more advanced than Penicillium. In the 

 former case, asci are borne naked and singly upon short branches from fer- 

 tile hyphae without any obvious development of a perithecial structure. 

 Such ascosporic strains are referred to Westling's genus Byssochlamys 

 (1909), which he regarded (and probably correctly so) as transitional 



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