''Hydnum rufescens'', commonly known as the terracotta hedgehog, is an edible

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basid ...

of the family

Hydnaceae The Hydnaceae are a family of fungi in the order Cantharellales. Originally the family encompassed all species of fungi that produced basidiocarps (fruit bodies) having a hymenium (spore-bearing surface) consisting of slender, downward-hanging ta ...

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

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. The origin of the word "cap" comes from the Old French word "chapeau" which means "head co ...

undersurfaces are covered by

hymenophore A hymenophore refers to the hymenium-bearing structure of a fungal fruiting body. Hymenophores can be smooth surfaces, lamellae, folds, tubes, or teeth. The term was coined by Robert Hooke Robert Hooke (; 18 July 16353 March 1703) was an ...

s resembling spines or teeth, and not pores or

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 ...

. It is very similar to the more common hedgehog fungus (''

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

''), and was previously sometimes considered a variety of that species. However, the following differences have been noted:Courtecuisse, R. & Duhem, B. (1994) "Guide des champignons de France et d'Europe" Delachaux et Niestlé , also available in English. *the cap of ''H. rufescens'' is russet rather than beige, *the overall dimensions are smaller and more regular in shape, with a central stipe, *the spines are not

decurrent ''Decurrent'' (sometimes decurring) 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 petio ...

, and *the

spore In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...

s are slightly larger. Both species are found in European

coniferous Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sin ...

and

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

forests growing on soil. It is reportedly

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

l with ''

Picea abies ''Picea abies'', the Norway spruce or European spruce, is a species of spruce native to Northern Europe, Northern, Central Europe, Central and Eastern Europe. It has branchlets that typically hang downwards, and the largest cones of any spruce, ...

'', ''

Pinus sylvestris ''Pinus sylvestris'', the Scots pine (UK), Scotch pine (US), Baltic pine, or European red pine is a species of tree in the pine family Pinaceae that is native plant, native to Eurasia. It can readily be identified by its combination of fairly s ...

'', ''

Fagus sylvatica ''Fagus sylvatica'', the European beech or common beech, is a large, graceful deciduous tree in the Fagaceae, beech family with smooth silvery-gray bark, large leaf area, and a short trunk with low branches. Description ''Fagus sylvatica'' i ...

'' and ''

Quercus robur ''Quercus robur'', the pedunculate oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native plant, native to most of Europe and western Asia, and is widely cultivated in other temperate regions. It ...

''.

References

''Hydnum rufescens''
at Northern Ireland Fungus Group URL accessed 11 June 2007 * Edible fungi Fungi described in 1800 Fungi of Europe Taxa named by Christiaan Hendrik Persoon rufescens Fungus species {{Agaricomycetes-stub