368 DISEASES OF CULTIVATED PLANTS 



A thoroughly good system of ventilation in the basement 

 of a building is of primary importance. 



DAEDALEA (PERS.) 



Substance corky or woody, pores on the under surface of 

 the pileus, becoming elongated and irregularly wavy, dissepi- 

 ments thick, corky, flexible when elongated. 



Distinguished from Trametes and Polyporus by the long, 

 irregularly contorted openings of the pores. A genus that 

 connects the gill-like structure of the hymenium of Agaricus 

 with the porous form of the hymenium in Polyporus. 



Daedalea quercina (Pers.). This fungus has been observed 

 growing on branch wounds of old oak-trees, and some people 

 suspect that it is a parasite. It is certainly not uncommon 

 on old trunks and stumps of oak in Britain. 



Said to be very destructive to railway ties in the United 

 States. 



Every part pale wood-colour. Pileus corky, rugulose and 

 uneven, in large specimens often much lobed, as if composed 

 of several confluent pilei, 4-10 in. across. Pores at first 

 roundish, becoming elongated, gill-like, and irregular, dis- 

 sepiments thick and elastic. 



Perennial. Pileus often with concentric, depressed zones. 



TRAMETES (FRIES.) 



More or less bracket-shaped, pileus hard, tubes originating 

 at various depths in the flesh of the pileus, and in this respect 

 differing from other members of the Polyporaceae. 



Some of the species have a pleasant spicy odour. 



Pine Trametes (Trametes pini. Fries.). This fungus is rare 

 in Britain, but according to Hartig it is very destructive in 

 the pine woods of North Germany. 



The fungus is a wound-parasite, and rarely attacks trees 

 under fifty years of age. 



Attached by a broad base, more or less triangular in 

 section, pileus rusty brown, then blackish, concentrically 

 grooved, rough, margin strigose, 3-4 in. broad, flesh rusty, 

 very hard ; tubes indistinctly stratified, bright rusty, pores 

 irregular in form. Hartig says a sporophore may live for 

 fifty years. 



