HYDNUM. 153 



Hydnum acre. Quelet. 



Pileus fleshy, compact, turbinate, depressed, tomentose, 

 yellowish-ochre, centre darker, flesh similarly coloured or 

 greyish, fragile, bitter and rather hot; stem short, rather 

 thick, darker than the pileus ; spines greyish-yellow, tips 

 whitish ; spores globose, spinulose, 6 //, diameter. 



Hydnum acre, Quel., Suppl. v. p. 324, t. vi. f. 1 ; Sacc. Syll. 

 vi. n. 6619. 



In sandy pine and chestnut woods. Known from allied 

 species by the hot acrid taste. 



** Pileus corky or coriaceous, tough. 



Hydnum compactum. Pers. 



Pileus 2-6 in. across, deformed, greyish-olive or brownish, 

 without zones, corky, compact, flesh variegated with blue ; 

 spines 1-2 lines long, brownish, tips paler ; stem about 1 in. 

 long, often deformed, brownish ; spores 6 /x diam. 



Hydnum compactum, Pers., Syn. 556 in part ; Stev., Fung., 

 p. 236. 



Amongst fir-trees, heather, &c. Often very irregular and 

 subsessile. Pileus often with white tomentum. 



Irregular, confluent, inodorous, resembling a thick, shape- 

 less crust. Pileus 1-6 in. broad, readily imbibing moisture, 

 clotted with down of the same colour, or dirty white. 

 Spines equal, chestnut ; stem corky, obsolete or very thick. 

 (Fries.) 



Hydnum aurantiacum. A. & S. 



Pileus 1-6 in. across, orange-yellow, corky, compact, 

 irregularly convex, with small protuberances, without zones, 

 often with white tomentum, flesh zoned; spines whitish, 

 changing to pale-brown, 1-2 lines long ; stem variable, ^-2 

 in. long, by ^1 in. thick, orange ; spores 34 //, diam. 



Hydnum aurantiacum, Alb. & Schw., p. 265 ; Stev., Fung., 

 p. 236. 



Inodorous, firm. In pine woods. 



Hydnum ferrugineum. Fries. 



Pileus 1-4 in. across, corky, soft, convex, then plane or 

 depressed, irregularly pitted, ferruginous, at first with 

 whitish tomentum, flesh ferruginous ; spines thin, acute, 



