In Europe the species is rather variable and possibly two cryptic species are involved (Maas Geesteranus, 1975). Sarcodon leucopus is reported from Siberia, Japan and North-America, but these records are considered here as doubtful. Conspecifity with European populations has to be proven.

Sarcodon leucopus is a spectacular hydnoid species with very large and striking basidiocarps. It has a wide distribution in Europe, possibly also in Siberia and North-America, but it is (very) rare everywhere, with a fragmented distribution area. It has become extinct in large parts of Western and Central Europe, mainly due to extreme sensitivity to nitrogen deposition (a component of acid rain). In Northern Europe it is mainly threatened by cutting of old pine stands.

Europe, Japan, possibly also Siberia and North-America (conspecifity has to be proven).

Sarcodon leucopus is rare and occurs on isolated localities throughout its distribution area. A strong decline has been reported from many regions and therefore it has been included in many National Red Lists: Extinct in the Netherlands (1849), Belgium (1882), Baden-Württemberg (1977); Critically endangered in Czech Republic, France, Germany; Endangered in Sweden and Switzerland; Vulnerable in Finland; Near threatened in Norway. The species is unknown from Great-Britain. In Japan only two records are known from Hokkaido. At present Norway is the centre of its global distribution with 95 known localities, mainly in Nordvestlandet. The trend of S. leucopus is negative, with an estimated decrease of at least 40% during three generations (50 years). According to forest statistics the decline of old pine forests in Scandinavia amounts to approximately 1% on an annual basis.

Sarcodon leucopus is an ectomycorrhizal symbiont of mature trees of Pinus sylvestris in old, often open coniferous forests on very dry, base-rich to calcareous soils with a very low nutrient status, often on thin soils above bedrock. In Norway S. leucopus is especially found in forests above olevine rocks, a habitat strongly threatened by quarrying.

Sarcodon leucopus is threatened in Western and Central Europe in the first place by increasing nitrogen deposition (air pollution). The critical load for this species is estimated at less than 15 kg N/ha/yr; a value exceeded now in almost entire Western and Central Europe, where the species has disappeared almost completely. In Northern Europe the species is mainly threatened by logging of old-growth pine forests, more locally also by quarrying for olivine.

Reduction of air pollution by limitation of nitrogen emissions by agriculture, traffic and industry; protection of old pine forests on base-rich mineral soils against clearcut.

Taxonomic research on homogeneity of the species in Europe (some characters are quite variable) and on posible conspecificity with populations from N. America and Siberia.

Arnolds, E. 2003. De stekelzwammen en Pruikzwammen van Nederland en België. Coolia 46: 1-96.
Maas Geesteranus, R.A.. 1975. Die Terrestrischen Stachelpilze Europas.
Nitare, J. 2006. Atgärdsprogram för bevarande av rödlistade fjälltaggsvampar. (Species action plan for red-listed Sarcodon. In Swedish with an English summary). Naturvärdsverket, rapport 5609. Stockholm.
Walleyn, R. & A. Verbeken. 1999. Een gedocumenteerde Rode Lijst van enkele groepen paddestoelen in Vlaanderen.