420 



THE FUNGI WHICH CAUSE PLANT DISEASE 



in thickness, usually found in imbricated masses projecting from 

 the trunks of living trees. Pileus subcircular and umbilicate when 

 young, soon becoming flabelliform and explanate; surface ochra- 

 ceous to fulvous, covered with broad, appressed, darker scales 



Fig. 301. — Polyporus squamosus. After Clements. 



which are very close together in young specimens; margin in- 

 volute, thin, entire; context fleshy-tough, juicy, milk-white; very 

 thick, odor strong; tubes decurrent, white or pale yellowish, very 

 short, mouths large, alveolar, 1 mm. or more in diameter, edges 

 thin at maturity, toothed at an early age, becoming lacerate: 

 spores broadly ovoid, smooth, hyaline, 5 x 12 m; stipe excentric 

 to lateral, obese, reticulate above, clothed at the base with short, 



