POLTPOEEI. 275 



substance reddish-brown, varying in density. Pores very minute, stratified, 

 whitish, glaucous, or yellomsh-grey, at length ferruginous, the mass of 

 them generally concave. — M. J. B. 



777. Polyporus nigricans. Fr. *' Black -hoof Polyporus." 



Pileus pulvinate, very thick, densely and concentrically sulcate, 

 smooth, shining, black, cuticle very hard, crustaceous, yarnished, 

 persistent, internally very hard, fen-uginons ; margin very obtuse, 

 ferruginous ; pores very small, plane, confluent, stratose, naked, 

 of the same colour. — Fr. Fpicr.p. "^(jQ. Eng.Fl. Y.p. 144. Bisch. 

 f. 3426. 



On birch. 

 Similar in form to P. fomentariv^y but manifestly distinct. 



778. Polyporus igniaxius. Fr. " Rusty-hoof Polyporus." 



Pileus at first tuberculoso-globose (immarginate), even, with 

 a thin flocculent crust which becomes white, then ungulate fer- 

 ruginous, becoming blackish-brown, opaque ; cuticle concrete, 

 pitted unequally, very hard, as well as the zoned, ferruginous 

 flesh ; margin rounded ; pores very small, convex, stratose, cin- 

 namon, at first whitish. — Fr. Epicr. p. 466. Lenz. f. 47. Fckl. 

 exs.no. 1383 {?) Soiv.t.lS'2. Mich. t. 62. Eng. Fl. y. p. lU. 

 Vent. t. 61,/. 4. Kl. exs.no. 363. 



On willows, poplars, plums, &c. Common. [United States.] 



The pileus is narrower and much thickerthan in P. /o?rt/e/tta/'<"//.?, resembling 

 a horse's hoof; margin obtuse, and the mass of tubes in general plane or 

 very convex. Occasionally the pileus is imperfectly developed. — M.J.B. 



779. Polyporus fulvus. Fr. " Tawny-hoof Polyporus." 



Pileus between woody and corky, very hard, globoso-tubercn- 

 lose, then triangular, subimbricate, at first hairy or villous, pale 

 tawny ; margin rounded, internally of the same colour, radiating 

 and zoned ; pores short, round, rather minute, cinnamon, at first 

 covered with a cinereous-yellow dust. — Fr. Epicr. p. 466. Rosth. 

 t.3l. Tratt. Aust.t. 5,/. 9. Batt.t. 37, H. B. 4' Br. Ann. N.U. 

 (1866), 7Z0. 1138. Br. Bath. Trans. 1810, p. 83. 



On decayed trunks. Batheaston. 



Distinct from P. igniaritts, to which it is allied. 



780. Polyporus rib is. Fr. " Currant-bush Polypoms." 



Pileus corky, coriaceous, rather soft, somewhat plane, velvety, 

 nearly even, ferruginous, then umber ; margin acute ; pores 



