Hydnellum fuligineoviolaceus is an ectomycorrhizal fungus with a wide distribution in Europe forming ectomycorrhiza with pine in older forest on mostly dry calcareous soil. It is conspicuous and easily identified, much searched after and is an extremely rare species throughout Europe.  The population in Europe population is small and fragmented and with typically only few mycelia at each locality. The European population is estimated to have declined, and continuing to decrease due felling of calcareous coniferous forests with long tree continuity.  It is nationally red-listed (VU - CR) in multiple European countries.

Decline in area and quality of available habitat has exceeded 30% over the last 50 years; the decline in population size over this time could be higher. This decline in habitat is expected to continue even more rapidly over the next 50 years (approximately three generations: one generation for the species is around 17 years). Currently the population size probably exceeds 5,000 mature individuals hence criterion A is applicable. This species meets the threshold for VU A2c+3c+4c.

Formally listed as a species of Sarcodon, this species is now clasified as Hydnellum (Larsson et al 2019). There are presently no known seqences of H. fuligineoviolaceum outside northern Europe (2024). The name has been used in North Ameria, but sequenced specimens refer to different taxa. Specimens namned S. fuligineoviolaceum outside Europe probably refers to other species.

Hydnellum fuligineoviolaceus is an European species with the largest subpopulations in Sweden, Norway and Spain.

Hydnellum fuligineoviolaceus is conspicuous and easily identified, much searched after. It is a very rare species throughout Europe and confined to a narrow habitat. The population in Europe population is widely spread, but small and fragmented and typically with a few mycelia at each locality only. It has its richest known occurrences in Sweden, Norway and Spain (Fraiture & Otto, 2015). The number of European sporocarp records in GBIF is about 1000 (2024). It is known from approx. 30 localities in Sweden, 13 localities in Norway, 3 localities in Finland, 11 sites in Spain according to data from national redlists and species database maps.In Sweden, the estimated total number of sites is 100 and in Norway 40 (SLU Artdatabanken 2021; Artsdatabanken 2021).

The total population size in Europe is estimated to approximately 250 localities, which is equalent to approximately 5000 - 7500 mature individuals, 3000 individuals.The European population is estimated to have declined, and continuing to decrease due felling of older calcareous coniferous forest. The decline is estimated to be in the range of 30-50% during the last 50 years. Nationally is red-listed in several European countries; Austria (CR), Estonia (CR), Finland (VU), Germany (CR), Norway (EN), Sweden (EN) and Switzerland (VU) (Dämmrich et al 2016, Dämon and Krisai-Greilhuber 2017, Hyvärinen et al 2019, Saar et al 2019, Senn-Irlet et al 2007, SLU Artdatabanken 2020, Artsdatabanken 2021).

The decline of the major habitat of the species, calcareous Pinus forests in the evaluation period of 50 years is estimated to be in the magnitude of 30-40% We estimate the decline of the species to be in the same magnitude. It is assessed as Vulnerable (VU) based on the criteria A2c+3c+4c.The lenght period of evaluation is 50 years (= 3 generations according to the recommendations of Dahlberg & Mueller, 2011).

Hydnellum fuligineoviolaceum forms ectomycorrhiza with Pinaceae; e.g. mainly Pinus sylvestris, but also with Abies alba, A.cephalonica and possibly Picea abies (Andre andOtto, 2015). It mainly inhabits nutrient poor dry calcareous soils, often acidified in the soil surface, with thin litter layer. In the Mediterranean and temperate regions it mainly occurs in pine forest, in the Alps, Abies forest are suitable habitat and in the northern European countries is mainly in older open Pinus forest (often with presence of Picea). Hydnellum fuligineoviolaceum is one of the Hydnellum species most strictly associated to calcareus soil (Nitare 2006, 2013). 

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The main threat is forest management, i.e. clearcutting. 

Protection of known localities. Information of its biology and conservation value.

Population biology is the primary needed research.

The species is not known to be used.

Artsdatabanken (2021). Norsk rødliste for arter 2021. (Red-listed species in Norway 2021).  Artsdatabanken, Trondheim. ISBN:  978-82-92838-56-3

Dahlberg A & Mueller G. 2011. Applying IUCN red-listing criteria for assessing and reporting on the conservation status of fungal species. Fungal Ecology 4: 1-16.

Dämmrich, F., Lotz-Winter H., Schmidt M., Pätzold W., Otto P., Schmitt J.A., Scholler M., Schurig B., Winterhoff W., Gminder A., Hardtke H.J., Hirsch G., Karasch P., Luderitz M., Schmidt-Stohn G., Siepe K., Täglich U. and Wöldecke K. (2016). Rote Liste der Großpilze und vorläufige Gesamtartenliste der Ständer- und Schlauchpilze (Basidiomycota und Ascomycota) Deutschlands mit Ausnahme der Flechten und der phytoparasitischen Kleinpilze.

Dämon, W and Krisai-Greilhuber, I. (2017). Die Pilze Österreichs. Verzeichnis und Rote Liste 2016.

Fraiture A & Otto P (ed) 2015. Distribution, ecology and distribution of 51 macromycetes in Europe. Result of ECCF Mapping. Programme.Meise, Botanic GArden Meise. Scripta Botanica Belgica 53.

Hyvärinen, E., Juslén, A., Kemppainen, E., Uddström, A. & Liukko, U.-M. (eds.) 2019. The 2019
Red List of Finnish Species. Ympäristöministeriö & Suomen ympäristökeskus. Helsinki. 704 p.

Larsson K-H, Svantesson S, Miscevic D, Kõljalg U and Larsson E. 2019.  Reassessment of the generic limits for Hydnellum and Sarcodon (Thelephorales, Basidiomycota).  MycoKeys 54: 31–47 doi: 10.3897/mycokeys.54.35386

Nitare, J. 2006: Åtgärdsprogram för bevarande av rödlistade fjälltaggsvampar. (Species action plan for red-listed Sarcodon. In Swedish with an English summary).  Naturvårdsverket, rapport 5609. Stockholm. ISBN: 91-620-5609-3.

Nitare J. 2023. Skyddsvärd skog: naturvårdsarter och andra kriterier för naturvärdesbedömning (In Swedish: Protected forest: nature conservation species and other criteria for nature value assessment). 3rd ed. Skogsstyrelsen. Jönköping. ISBN 987-91-986297-0-5

Saar I, Oja J, Põldmaa K, Pärtel K, Zettur I, Kõljalg U. 2019.  Red List of Estonian Fungi – 2019 update.  Folia Cryptog. Estonica, Fasc. 56: 117–126 https://doi.org/10.12697/fce.2019.56.12

Senn-Irlet B., Bieri G and Egli S. (2007). Rote Liste Grosspilze. Rote Liste der gefährdeten Arten der Schweiz Ausgabe 2007

SLU Artdatabanken (2020). Rödlistade arter i Sverige 2020. (Red-listed species in Sweden 2020) SLU, Uppsala ISBN 978-91-87853-54-8