''Hydnum'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately fr ...

in the family Hydnaceae. They are notable for their unusual

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...

-bearing structures of teeth rather than

gills A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

. The best known are the edible species ''

Hydnum repandum ''Hydnum repandum'', commonly known as the sweet tooth, wood hedgehog or hedgehog mushroom, is a basidiomycete fungus of the family Hydnaceae. First described by Carl Linnaeus in 1753, it is the type species of the genus '' Hydnum''. The fun ...

'' and '' H. rufescens''. There are no known toxic varieties of ''Hydnum.'' Widely regarded as important maintainers of forest eco systems, the ''Hydnum'' genus is known to have

ectomycorrhiza An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or my ...

l relationships with multiple plant families. ''Hydnum'' has many brittle, white teeth from which the spores drop. Some species have teeth which hang from ascending branches, while other species have teeth which project downwards from the undersurfaces of dead wood. Most ''hydnum'' are safe to eat, and contain many fatty acids and antioxidants.

Taxonomy and diversity

Hydnum are found on every continent that is habitable for plant life, with some preferring deep forest regions. Most of the common forms of hydnum, such as ''h. repandum'' and ''h. rufuscens'' can be located in Europe, East Asia, and Australia. ''Hydnum repandum'' is a common and edible variety of Hydnum. Also called the "hedgehog mushroom", ''h. repandum'' is most often found in Europe, Mexico, and North America. The white or buff ''

'' has a spore scatterer of still another shape. The smooth

cap A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...

grows as wide as 8 inches across, and the

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

is off-center and is less than 2 inches long. ''H.repandum'' is often confused in looks for its similar tasting cousin, the Chantrelle mushroom. Medicinally, ''h. repandum'' has shown promising signs in blocking cancerous sarcomas in mice. ''Hydnum rufescens'' is another common edible variety of hydnum. Known locally as the terracotta hedgehog mushroom, ''hydrufensces'' can be found in Portugal. It has been found to contain high levels of fatty acids and nutrients essential to the human diet. ''Hydnum minum'' is a new h''ydnum'' variety that was discovered in 2015. First located in Japan, ''Hydnum minum'' is identifiable by a "whitish basidiomata", or its spore-producing structure, and is distinctly its own species. ''Hydnum vesterholtii'' has been newly found in calcium rich areas of the Mediterranean, as well as in the Pyrenees and Italy, and is recognized by a ochre tinted spore cap. ''Hydnum ovoideisporum,'' much like '' hydnum vesterholtii,'' has an orangish colored pilei, or spore cap. It is also found in the Iberian-Mediterranian climate and is fond of calcium rich soils. *'' Hydnum albomagnum'' *'' Hydnum crocidens'' *'' Hydnum dispersum'' *'' Hydnum durieui'' *'' Hydnum elatum'' *'' Hydnum ellipsosporum'' *'' Hydnum investiens'' *'' Hydnum magnorufescens'' *'' Hydnum minum'' *'' Hydnum molluscum'' *'' Hydnum oregonense'' *'' Hydnum ovoideisporum'' *'' Hydnum papyraceum'' *''

'' *'' Hydnum rufescens'' *'' Hydnum umbilicatum'' *'' Hydnum vesterholtii''

References

{{Taxonbar, from=Q159023 Cantharellales Agaricomycetes genera