4i8 BRITISH FUNGI 



Readily known by originating under the bark, which becomes 

 cracked and curls back. 



On branches, esjoecially hazel. 



C. nigrescens. — Hymenium yellowish, becoming almost black 

 when exposed, 



f On branches, originating under the bark. Resembling C. 

 comedens in habit, but distinguished by being pale at first, and then 

 becoming blackish, whereas the last-named is purple when growing 

 and becomes pale when exposed by the rupture of the bark. Effused, 

 very thin, closely adnate, indeterminate ; hymenium waxy, pow- 

 dered with very large spores. 



Peniophora 



Resupinate fungi, entirely attached to the substance they are 

 growing upon, or with the edge free and more or less upturned ; 

 hymenium even, bristling with minute colourless hairs or cystidia. 

 Spores colourless. 



All the species form more or less expanded crusts on wood or 

 leaves. To the naked eye the hymenium appears to be perfectly 

 smooth, but under a good pocket lens is seen to be bristling with 

 numerous minute bristles. The genus Corticimn differs in the 

 absence of bristles in the hymenium. 



I. Edge free, upturned. 



P. quercina. — Forming patches of a circular or elongated form, 

 substance rather thick and cartilaginous, the edge becoming free 

 and upturned, blackish underneath ; hymenium reddish lilac, 

 flesh-colour or often slate-colour when old. 



On oak branches, rarely on other trees. 



P. pezizoides. — Bursting through the bark, starting as a small 

 cup-shaped body, gradually expanding. Much like P. quercina, 

 differing in the pale, downy under side. 



On dead branches of horse chestnut. 



P. gigantea. — Broadly extended, rather fleshy, cartilaginous 

 when dry ; hymenium whitish, minutely velvety, margin free, 

 more or less fibrous. 



Often forming patches of irregular form a foot or more in extent, 

 becoming tinged brown or lilac, and becoming smooth. 



On wood and bark of fir, etc. 



P. crosslandi. — Effused, thin, soft when moist ; hymenium 

 minutely setulose or hispid under a lens, grey, with a slight ochrace- 

 ous tinge when dry ; edge determinate, slightly raised, the whole 

 fungus separable from the matrix when dry (cystidia numerous, 

 conical, 30-40x10 /x above the hymenial surface, colourless and 

 studded with particles of lime ; spores elliptical, 6x3 1^). 



Resembling P. gigantea in being soft and fleshy when growing, 



