MUSHROOM GROWING 



or similar structures. The teeth may arise 

 from a true cap or from a tubercular, or 

 much branched structure. In form and 

 texture the members of this family differ 

 greatly and very few species possess a cen- 

 tral stem. The majority are tough or 

 woody, but some of the edible species are 

 extremely soft and delicate. No poisonous 

 species of this family have been reported. 



Edible Hydnums. Some members of 

 the genus Hydnum have a more or less 

 central stalk and a true pileus. In this 

 subdivision of the genus is found one spe- 

 cies of appreciable economic value, H. im- 

 brtcaiutn. This is a form of considerable 

 size, the cap, which is frequently irregular, 

 being eight to ten inches in diameter in ex- 

 treme forms. The upper surface is sooty 

 brown or mouse color and as it expands it is 

 differentiated or torn into scale-like areas, 

 sometimes with lighter markings or stria- 

 tions where the flesh shows through or is ex- 

 posed. The lower surface of the pileus is 

 densely beset with teeth, the color of which, 



178 



