Hydnum rufescens, commonly known as the Terracotta Hedgehog, is an edible basidiomycete

Basidiomycota

Basidiomycota is one of two large phyla that, together with the Ascomycota, comprise the subkingdom Dikarya within the Kingdom Fungi...

 of the Family Hydnaceae

Hydnaceae

The Hydnaceae are a family of fungi in the order Cantharellales. Originally the family encompassed all species of fungi that produced basidiocarps having a hymenium consisting of slender, downward-hanging tapering extensions referred to as "spines" or "teeth", whether they were related or not...

. It belongs to the small group of mushrooms often referred to as the tooth fungi, which produce fruiting bodies

Sporocarp (fungi)

In fungi, the sporocarp is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne...

 whose cap undersurfaces are covered by hymenophore

Hymenophore

A hymenophore refers to the hymenium-bearing structure of a fungal fruiting body. Hymenophores can be smooth surfaces, lamellae, folds, tubes, or teeth....

s resembling spines or teeth, and not pores or gills.

It is very similar to the commoner hedgehog fungus (Hydnum repandum), and is sometimes considered a variety of that species. However the following differences have been noted:

• the cap of H. rufescens is russet rather than beige,
• the overall dimensions are smaller and more regular in shape, with a central stipe
  Stipe (mycology)
  thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
  
  ,
• the spines are not decurrent
  Decurrent
  Decurrent is a term used in botany and mycology to describe plant or fungal parts that extend downward.In botany, the term is most often applied to leaf blades that partly wrap or have wings around the stem or petiole and extend down along the stem...
  
  , and
• the spores are slightly larger.

Both species are found in European coniferous and deciduous

Deciduous

Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...

 forests growing on soil. It is reportedly ectomycorrhizal with Picea abies, Pinus sylvestris, Fagus sylvatica and Quercus robur.