102 
HYMENOMYCETES 
first sight be mistaken for a tuft of agarics. In woods, in 
early aut.; terrestrial, or on stumps. 
P. sulphureus (from the sulphur colour), “ Cheesy-yellow 
Polypore.” Plate XXXIII. 5. 
P. undulate, tufted and imbricated, 6-12 in. diam. or more, 
yellowish-orange or reddish. F. thick, yellow becoming 
white, of a cheesy consistency, never leathery. T. up to J in. 
long. Pov , minute, plane, always a beautiful sulphur-yellow. 
The pileus is covered with crystals of oxalate of lime. A 
large showy species; frequent on living trunks in aut. and 
early win.; one of the few fungi that attack the yew. Brittle. 
Smell disagreeable, becoming very powerful when drying. 
P. betulinus ( betula , birch — its habitat), “ Birch-tree 
Polypore.” Plate XIII. 7. 
P. corky, hoof-shaped, whitish at first, then pale reddish- 
brown, zoneless, glabrous, margin incurved, 3-8 in. diam. or 
more. F. white, very thick. Pov. up to \ in. deep, unequal, 
whitish. Very common on living and dead birch. Some¬ 
times the hymenium is attacked by parasitic moulds, 
Hypomyces rosellus and Hypocrea ochracea. 
P. fumosus (fumosus, smoky—from its colour). Plate 
XXXIII. 1. 
P. 2-5 in., horizontal, often imbricated, effused behind, 
smoky grey. F. whitish, fibrous, rather corky, up to J in. 
thick. Pov. shallow, small, rounded, greyish-white, darker 
when bruised, not becoming black in drying. Common in 
late aut. and early win. on old trunks and stumps. 
P. adustus ( aduro , to burn—from the scorched appearance) 
differs from the above in the thinner substance and very 
minute pores which become blackish when dry. 
The bay-brown species which frequently forms enormous 
imbricated flaps at the base of living beeches in aut. is 
P. giganteus. 
