 Hydnellum is a genus of tooth fungi of the family Bankeraceae in the order Thelephorales . Widely distributed in the Northern Hemisphere , the genus contains around 40 species . The fruitbodies of its members grow by slowly enveloping nearby bits of grass and vegetation . There is great variability in the form of Hydnellum fruitbodies , which are greatly influenced by environmental conditions such as rainfall and humidity , drying winds , and temperature . They are too tough and woody to eat comfortably . Several species have become the focus of increasing conservation concern following widespread declines in abundance . 
