FLESHY AND WOODY FUNGI 221 



Family 4.. Thelephorace.^. — Fruit bodies of a simple type are 

 found in this family. They form on three trunks, either flat 

 leathery crusts with the hymenium on the smooth upper surfaces, or the 

 flat fructifications are raised above the substratum and have bracket- 

 like outgrowths, which show an overlapping arrangement with the 

 hymenial layer on the under side. The important genera are Corticium, 

 Stereum and Thelephora. In Corticium, the fructification is leathery, 

 membranous, fleshy, rarely wholly gelatinous, crust-like, growing resu- 



FiG. 85. — a piece of old oak timber rotted by Slereum fruslulosum showing scat- 

 tered frvtiting bodies. {After von Schrenk, Hermann, Bull. 149, U. S. Bureau of 

 Plant Industry, 1909.) 



pinate. The hymenium is smooth, or pimply, and consists of club- 

 shaped basidia with four basidiospores. The species are mostly 

 found on wood. C. vagiim-solani in its sterile form is known as Rkiz- 

 octonia, which apparently has been found on sugar beet, bean, carrot, 

 cabbage, potato, egg plant and a number of other hosts. The hymeno- 

 phore of this species is white with short basidia and elliptic spores. 

 It frequently entirely surrounds the green stems of its host near the 

 ground. The persistent hymenophore of Stereum is leathery, or 



