CHAPTER XXIX 



TREMELLALES 



In the Tremellales, we return again to the threshold of the Basidio- 

 mycetes. They represent the chiastobasidial counterpart of the Auricu- 

 lariaceae and have rounded, pyriform basidia, longitudinally divided 

 into four cells. They begin as the Polyporales with forms without well- 

 developed fructifications and end with forms having gymnocarpous 

 or even angiocarpous fructifications. The gymnocarpous species are 

 placed in the Tremellaceae, the angiocarpous ones in the Hyaloriaceae, 

 while two species of doubtful position are placed in the sirobasidiaceae. 

 Their most marked morphological relationships are shown in the scheme 

 below. 



TREMELLALES 



Diagram XXXI. 



Tremellaceae. — This family forms a series parallel to the Poly- 

 porales, developing from arachnoid coverings to compact, bilateral, 

 gymnocarpous fructifications. According to the structure of these 

 fructifications, they may be divided into four subfamilies: the Sebacineae, 

 the Tremelleae, the Protomerulieae and the Tremellodonteae. 



The Sebacineae correspond to Corticium of the Corticiaceae. In 

 the primitive forms with cruciate basidia, there is no well-defined hymen- 

 ium, the basidia appearing irregularly scattered on the mycelial felt. 

 Sebacina papillata (Stypella papillata) and S. minor (Stypella minor) 

 (Moller, 1895) on mouldy wood in Brazil, form small, gelatinous cover- 

 ings with papillose elevations which consist of peculiar, long, tubular, 

 aseptate cells (Fig. 339, 1). At the ends of hyphae, the cruciate basidia 



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