Wood hedgehog

Overview

The wood hedgehog, Hydnum repandum, is a wild mushroom with a dry, smooth cap and a dense layer of whitish spines on its underside rather than gills. It forms a mycorrhizal partnership with trees in both coniferous and deciduous woods, and it grows singly, scattered or in groups, sometimes in fairy rings. In Europe it is one of the best-known wild edible fungi.

The species is described as a choice edible. Sources say its flavour is mild, sweet and nutty, and its texture firm and crunchy. Older specimens can taste bitter, so the quality of the picked fruit body matters.

Names and taxonomy

Carl Linnaeus described the species in 1753, and Elias Magnus Fries sanctioned the name in 1821. It is the type species of the genus Hydnum, whose name comes from a Greek word for truffle. Older names include Dentinum repandum and Sarcodon repandus. Common names include wood hedgehog, sweet tooth, pig's trotter and yellow tooth fungus. In France it is sold as pied-de-mouton, meaning sheep's foot, and in Germany it is known as Semmelstoppelpilz.

Variety rufescens, a smaller and deeper apricot-orange form, is treated as a synonym of H. rufescens by Wikipedia. Variety album is the white form, called white wood.

Description

The cap is orange, yellow or tan and up to 17 cm wide, though larger specimens are recorded. It is dry, smooth, often irregular, with a wavy margin. The spines are whitish, 2 to 7 mm long, and sometimes run down the stipe. The stipe is 3 to 10 cm long, white or cap-coloured, and sometimes off-centre. The flesh is white, firm and brittle, and bruises yellow to orange-brown. The spore print is pale cream, and the spores are smooth and roughly spherical to broadly egg-shaped.

Habitat and distribution

The species is mycorrhizal and fruits from summer to autumn. Wikipedia names no specific host tree for Europe, and it notes an association with oaks in eastern North America. It is widely distributed in Europe, the Pacific Northwest and the Rocky Mountains, and is not recorded in Canada. Its conservation status varies: it is listed as vulnerable in the Netherlands, Belgium and Germany, and as Least Concern in Sweden.

Look-alikes

The spines separate it from gilled species, and the sources say no poisonous mushroom shares this feature. Look-alikes named in the sources include the white hedgehog (H. albidum) and the giant hedgehog (H. albomagnum) of North America, H. umbilicatum, which has a navel-like cap and larger spores, H. rufescens, which is smaller with a deeper apricot-orange cap, and H. ellipsosporum, a German species with ellipsoid spores.

Preparation and use

Cooks sauté or fry the fruit bodies, simmer them in milk or stock, pickle small specimens, and use them in white wine or cream sauces. The fungus freezes well. Older or wormy specimens taste bitter and have a tougher texture; boiling can remove the bitterness. Specimens under conifers can taste unpleasantly strong.

The form amarum is reported as inedible because of bitterness at every stage of growth. The sources do not give a recommended preparation for every case.

Safety

Wikipedia gives no toxicity rating for the species beyond its statement that there are no poisonous look-alikes. It also reports that European fruit bodies accumulated caesium after the 1986 Chernobyl accident, at a high rate. The sources reviewed give no safe quantity.

Appearance, smell and taste do not establish that a mushroom is safe to eat. Wild fungi can carry environmental contaminants, so identify the species with an experienced expert and follow official food safety advice before eating any wild mushroom.

Open questions

The sources do not give a dated record of food use before the cookbook references, a cultivation history, or the caesium level in specimens sold today. The species is not farmed, according to the trade sources reviewed. These are unknown, not negative findings.