 The fungus is classified in the stirps ( species thought to be descendants of a common ancestor ) Diabolum of the genus Hydnellum , a grouping of similar species with the following shared characteristics : flesh that is marked with concentric lines that form alternating pale and darker zones ( zonate ) ; an extremely peppery taste ; a sweetish odor ; spores that are ellipsoid , and not amyloid ( that is , not absorbing iodine when stained with Melzer 's reagent ) , acyanophilous ( not staining with the reagent Cotton Blue ) , and covered with tubercules ; the presence of clamp connections in the hyphae . Molecular analysis based on the sequences of the internal transcribed spacer DNA of several Hydnellum species placed H. peckii as most closely related to H. ferrugineum and H. spongiosipes . 
