310 THE BASIDIOMYCETES 



since at maturity the peridium may surround the gleba com- 

 pletely or may merely surmount it to form a pileate structure on 

 the lower surface of which the gleba is exposed. The gleba in- 

 variably is borne around a central columella, which is in reality 

 a prolongation of the stalk of the fruiting body. Approximately 

 70 species of this order are classified in 2 famiHes: the Secotiaceae, 

 in which the gleba does not break up at maturity into a dry 

 powdery mass, and the Podaxaceae, in which the gleba disinte- 

 grates when ripe. 



The Family Secotiaceae is typified by Secotium, which is 

 world-wide in distribution and has approximately 25 species. The 

 genus is most common in Australia and New Zealand [Cunning- 

 ham (1924)], but one representative, S. {Endopty chum) agari- 

 coideSy is found in the eastern United States. The development 

 of S. agaricoides has been studied by Conard (1915) and Lohwag 

 (1924), and two other species of Secotium have been investigated 

 by Cunningham (1925). The fructification is completely angio- 

 carpous, the thick peridium surrounding the gleba being fused 

 with the stalk below. The gleba becomes divided into irregular 

 masses by tramal plates, which may originate either from the 

 inner surface of the peridium or from the columella and may 

 become lamellate. The development of the four-spored basidia 

 is characteristic of basidiomycetes in general. The spores, which 

 may be either smooth-walled or warted, are liberated by a break 

 in the peridium arising from elongation of the stalk and columella. 

 According to Cunningham (1925), the spores become binucleate 

 upon germination and thus give rise directly to a dicaryotic my- 

 celium. 



In the closely related Family Podaxaceae, Podaxis (Podaxon) is 

 chiefly African in its distribution but may also be found in the 

 western United States. The genus has been studied taxonomically 

 by Massee (1890) and Patouillard (1890). In general appearance 

 Podaxis is larger and more slender than Secotium. The friable 

 outer surface of the peridium is shaggy or scaly and is confluent 

 with the stalk both above and below the gleba. The glebal 

 chamber is at times traversed by slender capiUitial threads. 

 Within the gleba are masses of basidia, each of which bears four 

 sessile spores. Liberation of the spores begins, as in Secotium, by 

 rupture of the peridium below the gleba as a consequence of 

 elongation of the columella; the gleba, however, matures pro- 



