RHIZINA. 



273 



Fr. {Rh. inflata, Schaeff.). Eoot fungus, or Ring-disease.-^ This 

 fungus is found as a saprophyte on the earth, especially where 

 forest fires have occurred ; also as a parasite on indigenous and 

 exotic conifers. As such it has been observed in nurseries in 

 various parts of Germany, and in woods of Pinus Pinaster in 

 France. The fungus itself is known in Britain, though not as 

 a parasite. 



^ 



Fig. 144. — Sporophores of Kkizina v/adulata. 

 <t. Upper surface ; &, lower surface ; c, small 

 sporophores. (After Hartig.) 



Pig. 145.— Section of hymenium. a. Para- 

 pbyses; 6, eecreting-tubes ; c, asci, each with 

 eight spores. (After Hartig.) 



The disease extends from a centre and attacks one plant 

 after another, causing them to lose their needles and die. 

 The sporophores are large (f to 2 inches), chestnut-brown, 

 flattened or undulating structures, which sit directly on the 

 mycelium, without a stalk. On the upper surface is the 

 ascogenous layer which, when moist, is peculiarly sticky and 



iR. Hartig, Forstl-naiunvissen. Zeitschrift. , 1892, p. 591; Prillieux, Compt. 

 reiid. de la Soc. des Agric, 1880. 



S 



