THE FUNGI WHICH CAUSE PLANT DISEASE 439 



Favolus Fries (p. 417) 



Sporophore leathery, fleshy, or coriaceous, laterally stipitate; 

 hymenium with large elongated pores which may even become 

 lamellate, Fig. 311. 



A genus of some seventy species. 



F. europaeus Fr. is a European parasite of fruit and nut trees; it 

 is also common in America. 



Dsedalea Persoon (p. 417) 



Hymenophore epixylous, usually large and annual, sessile, 

 applanate to ungulate; surface anoderm, glabrous, often zonate: 

 context white, wood-colored or brown, rigid, woody, tough or 

 punky: hymenium normally labyrinthiform, but varying to lamel- 

 late and porose in some species: spores smooth, hyaline. 



About seventy-six species. Fig. 312. 



D. quercina (L.) Pers. 



Pileus corky, rigid, dimidiate, sessile, imbricate, applanate, 

 convex below, triangular in section, 6-12 x 9-20 x 2-4 cm. ; surface 

 isabelline-avellaneous to cinereous or smoky-black with age, 

 slightly sulcate, zonate at times, tuberculose to coUiculose in the 

 older portions; margin usually thin, pallid, glabrous; context 

 isabelline, soft-corky, homogeneous, 5-7 mm. thick; tubes laby- 

 rinthiform, becoming nearly lamellate with age in some specimens, 

 1-2 cm. long, 1-2 mm. broad, chalk-white or discolored within, 

 edges obtuse, entire, ochraceous to avellaneous. 



Common on oak and chestnut,*'^ often on living trees but 

 growing only on the dead wood. 



Lenzites Fries (p. 417) 



Hymenophore small, annual, epixylous, sessile, conchate; 

 surface anoderm, usually zonate and tomentose: context white or 

 brown, coriaceous, flexible; hymenium lamellate, the radiating 

 gill-like dissepiments connected transversely at times, especially 

 when young: spores smooth, hyaline. Fig. 313. 



About seventy-five species. 



