532 CLASS BASIDIOMYCETEAE 



Boletaceae and Agaricaceae. The gymnocarpic origin or pseudoangio- 

 carpic origin of the hymenial surfaces is found in Hemigaster (Juel, 1895), 

 Chamonixia, Hydnangium, Arcangeliella, Elasmomyces, and probably 

 other forms. In the majority of genera however, the development is 

 angiocarpic. 



The structure of the spore fruits is not at all on a common plan but 

 they are very heterogeneous. It is not certain that the 1200 to 1500 species 

 included in about 120 genera form a group of monophyletic ancestry. 

 Certain genera are beyond doubt closely related to the Agaricaceae and 

 may have arisen from that family or may be, as Lohwag (1925), Singer 

 (1936 and 1950) and others have suggested, in the ancestral line leading to 

 those fungi. If these are excluded from the Gasteromyceteae the re- 

 mainder form a more coherent group. 



The structure of the basidiospores is of several types and probably 

 should be given further study with reference to its importance in the 

 determination of the relationship of the genera. The more or less lemon- 

 shaped spore with dark color and warty surface is very striking. This type 

 is found in Gasterella and Gasterellopsis, Hymenogaster, Chondrogaster, 

 Dendrogaster, and perhaps others. The spores in the Phallales are smooth, 

 ellipsoidal to cylindrical, and nearly colorless. In many genera the spores 

 are spherical and spiny, in others smooth. In Podaxis the spore is plainly 

 two layered, with a terminal germ pore. In Gautieria and Chamonixia the 

 spores are longitudinally ridged and furrowed, as in Clitopilus and Octo- 

 juga in the Agaricaceae. In Nigropogon they are angled, somewhat as in 

 Rhodophyllus {Entolmna) in that family. Until the ontogeny of the spore 

 fruits from their earliest stages has been studied it is uncertain to what 

 degree these different spore types represent relationships within or with- 

 out the Gasteromyceteae. 



In Secotium, Elasmomyces and Gasterella, and some other forms cys- 

 tidia are present in the hymenium. This has been considered by some 

 investigators to indicate relationship with the Hymenomyceteae. In 

 Arcangeliella latex vessels are present and also in Lactariopsis (which may 

 perhaps better be placed in the Agaricaceae close to Lactarius). They are 

 also described in Battarrea and Phellorinia. 



Since the youngest stages of development of the spore fruit have not 

 been studied, except in a relatively small number of the subterranean 

 genera, and also are unknown in many of the tropical species whose earlier 

 stages are not subterranean, the relationships of these fungi to other groups 

 and the interrelationships of the genera and families making up the 

 Gasteromyceteae are still far from settled. 



In general there appear to be four types of structure, as pointed out by 

 Lohwag (1924b, 1925, 1926) and Eduard Fischer (many publications, 

 especially in Engler and Prantl, 1933). These may be called the lacunar, 



