 Karsten 's original 1879 circumscription of Hydnellum contained 19 species . Joost Stalpers included 34 Hydnellum species in his 1993 monograph on the Thelephorales . The tenth edition of the Dictionary of the Fungi ( 2008 ) indicated 38 species in the genus . As of January 2015 , Index Fungorum lists 39 species of Hydnellum . 
