HYDXEAE. 147 



Sistotrema. — Pileate ; fleshy, central-stemmed, teeth flat- 

 teued, irregular, inferior. 



Irpex. — Eesupinate ; teeth rather acute, springing from folds 

 or ridges that often anastomose irregularly. 



Radulum. — Eesupinate ; tubercles coarse, deformed, suhcy- 

 lindrical, obtuse. 



Phlebia.^ — Eesupinate ; hymenium covered with folds or 

 wrinkles, having the edge entire or corrugated. 



Grandinia. — Eesupinate ; hymenium with crowded, globose, 

 jDersistent, hemispherical, minute granules, having 

 their apices more or less excavated. 



Porothelium. — Eesupinate ; hymenium with scattered, 

 wart-like granules, which become more or less elou 

 gated and excavated at the apices. 



Odontia. — -Eesupinate; hymenium densely covered with 

 small granules that are divided at the apices in a 

 penicillate manner. 



Kneiffia. — Eesupinate ; hymenium covered with very minute ,. 

 barren, acute spinules. 



Mucronella. — Spines slender, elongated, acute, not spring- 

 ing from a sporophore or subiculum. 



HYDNUM. Linn. (figs. 1, 2, p. 149.) 



Hymenium inferior in the higher species, superior in resu- 

 pinate forms, covered with acute, awl-shaped spines that are 

 perfectly distinct at the base. Basidia tetrasporous. 



Hifhvnn, Linn., Gen. El., n. 968; Stev., B. Fung., p. 233. 



Tlie central genus of the Hijdneae, distinguished from Irjjex,. 

 its nearest ally, by having the pointed spines free at the base,. 

 that is, not originating from folds or wrinkles, but fi'om the 



L 2 



