One of the better-known species is the unusual pinkish-white Hydnellum peckii, also known as "strawberries and cream" or as the "bleeding tooth fungus" due to the red droplets that appear on the pinkish or whitish fruitbodies.

The genus was not in Donk's original family concept, which included only Bankera and Phellodon, genera whose species produce hyaline (translucent), and ornamented spores.

[6] In 1981,[7] however, Walter Jülich emended Donk's concept of the Bankeraceae, adding hydnoid genera that produced brown, lobed spores—Hydnellum and Sarcodon.

This intermittent growth affects the fruitbodies of different species to variable extents, leading to large variations in form, surface texture, and color.

[25] The morphological variability of fruitbodies and the dependence of their appearance upon environmental conditions has made Hydnellum a difficult group to study.

[18] The caps form from the top of the short stipe by the growth and expansion of a blunt margin and later as a thickening of the upper surface.

[27] The genus is widely distributed in the Northern Hemisphere, particularly Europe and North America,[28] but some species are also found in tropical Asia.

[19][29][30] Rudolph Arnold Maas Geesteranus recognized 16 European species in his 1975 treatment of the genus,[31] to which H. dianthifolium has been recently added by Loizides and colleagues.

[16] Some Hydnellum species, including H. ferrugineum and H. scleropodium, form a tough mat of mycelia in the humus and upper soil of pine forests.

These areas generally lack dwarf shrubs and promote the vigorous growth of mosses; reindeer lichens often occur in the center of large mats.

[32][33] Some Hydnellum species have been shown to be in decline in Europe, including the Czech Republic,[34] the Netherlands,[35] Norway,[36] and Scotland.

[38] H. ferrugineum and H. peckii are sensitive to the increased nitrogen deposition resulting from clear-cutting, a forestry practice used in some areas of Europe.

[15][14] 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.

[40] 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.

[42] Atromentin also possesses antibacterial activity, inhibiting the enzyme enoyl-acyl carrier protein reductase (essential for the biosynthesis of fatty acids) in the bacteria Streptococcus pneumoniae.

Hydnellum caeruleum, used in North America and Scandinavia to dye silk and wool, produces a range of colors including tan, blue, and forest-green, depending on the mordant that is used.

[47] This compound, derived metabolically from the shikimic acid pathway, inhibits the enzyme prolyl endopeptidase, which is involved in deteriorating certain neuropeptides that are believed to contribute to memory and learning.