THELEPHOEA. 429 



THELEPHOREAE. 



Thelephora. 



The sporophores of this genus assume very varied forms, from 

 simple incrustations to mushroom-like structures. They consist 

 of two layers only, the middle one being absent. The basidia 

 are club-shaped and produce four roundish or oval, hyaline or 

 light-coloured spores. 



Thelephora laciniata Pars, is not a true parasite, yet it is a 

 dangerous enough enemy to trees. In damp situations, it is 

 common and thrives, growing over young trees and so enveloping 

 them with its sporophores that suffocation ensues. (Britain and 

 U.S. America.) 



Th. pedicellata Schw. has been reported from America ' as a dangerous 

 parasite on apple, Quercus coccinea, and a palm. 



Th. perdix Hartig, a parasite on oak-wood. (See Stereum fribstulosum.) 

 Helicobasidium Mompa. Ichik.^ This is injurious to the mulberry tree 

 near Tokyo, Japan. It first attacks the roots, and in consequence the 

 growth of shoots is arrested, the young leaves die oflf, and gradually death 

 of the tree follows. The mycelium permeates the tissues of the host, and 

 forms an external velvety coating of basidia. 



Stereum. 



Sporophores generally differentiated into three layers, and 

 forming leathery or woody encrustations, or ilattened hemi- 

 spherical structures attached by one edge only. 



Stereum hirsutum (W.) Fr. White-piped or yellow-piped oak. 

 (Britain and U.S. America.) A very common fungus, occurring as 

 a saprophyte on dead branches, on boards, and posts of various 

 kinds of timber, as well as parasitic on living wood, particularly 

 on oak. 



The sporophores first appear as crusts, later they become 

 cup-shaped ; externally they are brown and roughly hairy with 

 acute yellowish margins. The smooth hymenial layer is orange- 

 red and marked by zones. Between the sterile leathery sporo- 

 phore and the hymenial layer there lies a firm white 

 intermediate tissue. 



^Galloway, Journal of Mycology, vi., p. 113. 



^Nobujiro Ichikawa, "A new hymenomycetous fungus,'' Jour, of College of 

 Science. Imperial University, Japan, 1890. 



