THALLOPHYTES 87 



coming to the surface, after having broken through the epidermis. These 

 basidia, each bearing four spores, arise directly from the mycelium, without any 

 complex sporophore formation, differing in this respect from the following groups. 



(g) Thelephorales 



The sporophores of these forms appear on tree trunks as flat and tough leathery 

 incrustations, the hymenium spreading over the smooth upper surface ; or as 

 brackets raised above the substratum, the hymenium extending over the under 

 surface; or as funnel-shaped bodies lined with the hymenium. The general char- 

 acter of the sporophore distinguishes this group from the next ; and the indefinite 

 extent of the hymenium over the sporophore distinguishes both groups from those 

 which follow. 



(h) Clavariales 



These are the coral fungi, with fleshy sporophores that often simulate branching 

 coral in form, the hymenium covering the whole surface of the branches. There 

 are also unbranched, club-shaped sporophores ; but all are characteristically 

 fleshy and hymenium-covered. 



(i) Agaricales 



This is by far the greatest group of fleshy fungi, containing most of 

 the so-called mushrooms and toadstools. The complex sporophore is 



FIG. 197. Lepiota : a common edible mushroom. After COULTER. 



usually definite in form, being differentiated into stipe and pileus (fig. 

 197), the latter having special surfaces for the hymenium. The prin- 

 cipal families are as follows : 



