CHAPTER XXX 

 CANTHARELLALES 



The Cantharellales ascend, as do the Polyporales, from resupinate 

 types to gymnocarpous forms. Anatomically, even the highest forms 

 retain primitive characters, the uniform structure and slight differentia- 

 tion of hyphal tissue, hymenophore and hymenium. The basidia corre- 

 spond to the stichobasidial type, simple in form and variable in spore 

 number. The diploid nucleus (as in asci) generally proceeds through 

 three divisions, hence the young basidium is octonucleate and in this 

 condition appears entirely similar to a Hypocreaceous or a Discomycetous 

 ascus (Fig. 353, 3). Similarly, in some species, usually eight basidio- 

 spores are formed; in others, in spite of the octonucleate basidia, the 

 spore number is reduced and finally fixed at a two-spored type, although 

 the stichobasidial method of division is retained (Fig. 353, 10). These 

 two-spored basidia suggest conditions we will find in the Dacryomyce- 

 tales, since their sterigmata often swell at the base, forming a cone. 

 Perhaps both orders have developed from simple resupinate crusts with 

 normally eight-spored basidia. At present no imperfect forms are known, 

 but two parasitic genera have been reported to form sprout mycelia. 



As already briefly indicated on page 427, the Cantharellales is only a 

 provisional order. This transitional state is explained by the lack of 

 cytological information. Until this has been obtained, it seems better 

 to leave the species in the chiastobasidial orders, which are much larger 

 and have realized more varied possibilities of development than the 

 stichobasidial type. Therefore we will place in the Cantharellales only 

 those forms in which stichobasidia have been demonstrated, and make 

 no nomenclatorial changes to carry out this classification. The value 

 of this separation of the stichobasidial types from the chiastobasidial 

 types is extremely doubtful (Juel, 1916). 



These forms may be placed in three families: the Exobasidiaceae, 

 resupinate forms, often modified by their parasitism, usually lacking a 

 compact hymenium, so that their basidia emerge singly or in groups from 

 the stomata of the host; the Clavulinaceae with fructifications similar to 

 those of the Clavariaceae discussed in the Polyporales; and the Cantharel- 

 laceae, whose fructifications are differentiated into pileus and stipe. 

 Their possible phylogenetic relations are shown in the following diagram : 



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