438 THE FUNGI WHICH CAUSE PLANT DISEASE 



ferruginous to grayish-umbrinous, glistening when young, rather 

 thin, entire; spores subglobose, smooth, hyaline at maturity, 

 becoming brownish with age, 5-6 x 3^ ti; spines abundant, short, 

 25-35 X 4-6 M- 



It occurs on pine, spruce, larch, hemlock, and fir as a wound 

 parasite of the heart wood; it is also on willow in Europe and 

 America. 



The spores are wind-borne and, lodging on improtected sur- 

 faces, develop a mycelium which grows both up and down, spread- 

 ing most rapidly in a longitudinal direction, or horizontally follow- 

 ing an annual ring. The fungous enzyme first dissolves the lignin 

 leaving the individual tracheids free and of nearly pure cellulose. 

 The cellulose is later dissolved, resulting in holes in the wood. 

 It is found on most of the conifers of the United States as a sapro- 

 phyte. The wood becomes white-spotted. In late stages of decay 

 the entire wood is full of small holes which are lined with a white 

 fungous felt. 



T. ribinophila Murr. is perhaps a parasite on the black locust. 



T. theae Zimm. cause a root- 

 rot of tea in India.'' 

 T. suaveolens (L.) Fr. 

 Pileus large, subimbricate, 

 dimidiate, sessile, convex above, 

 plane or concave below, 4-6 x 

 5-12 x 1-3 cm. ; surface smooth, 

 anoderm, azonate, finely villose- 

 tomentose to nearly glabrous, 

 white to pale-isabelline; margin 

 thick, sterile, entire: context 

 white, punky-corky, 1-2 cm. 

 thick, very fragrant when fresh. 

 Fig. 311— Favolus europaeua. with the odor of anise; tubes 5- 



°^ ■ 15 mm. long, white within, 



mouths circular, 2 to a mm., edges at first very thick, white, entire, 

 becoming thinner and often blackish with age: spores oblong-ovoid, 

 subsinuate, smooth, hyaline, 8-9 x 3-5 m; hyphae 7 m; cystidia 

 none. 



On willow. 



