 Conservation efforts for Hydnellum are hindered by the fact that some species are difficult to discriminate in the field , making it hard to determine an appropriate conservation status . Techniques based on species @-@ specific PCR primers and DNA extraction from soil have been developed to detect the mycelia of various Hydnellum species without having to rely on the presence of fruitbodies , which may help conservation efforts as well as improve understanding of below @-@ ground ecology . Similar techniques have been used to show that , in the case of H. aurantiacum and H. caeruleum , the fungus can persist below the ground for at least four years without producing fruitbodies . 
