Shingled hedgehog

Description

The scaly tooth has a large brown cap, up to 15–25 cm across, covered with coarse, dark scales arranged like roof tiles. With age the centre of the cap sinks into a funnel shape and the margin becomes wavy. The underside has neither gills nor tubes, but crowded, brittle, greyish-brown spines running down the stipe. The flesh is white to greyish-brown and smells spicy.

It grows from August to October in coniferous forests, mainly under spruce, in the mountains and on acidic or sandy soils, singly or in groups. In Poland it is on the Red List as a species threatened with extinction, although it can be locally common; it is no longer under species protection.

It is distinguished from the very similar pine scaly tooth mainly by where it grows: under spruce or under pine. Hydnellum species usually have smaller caps, bitter flesh and colour changes in the stem. If you are not sure of the species, do not pick it or eat it.

Identification features

Cap

Thick-fleshed, usually 6–25 cm in diameter (some descriptions also give a maximum of 15 or 30 cm). Flat-convex, becoming funnel-shaped and depressed with age; the margin is at first inrolled, later lobed and wavy. Colour brownish with a slight reddish tinge, or buff. The surface is covered with coarse, dark brown, concentrically arranged scales, which darken and become upturned with age.

Hymenophore (underside of the cap)

Instead of gills or tubes, there are spines about 0.5–1.5 cm long, crowded, soft and brittle, running down the stipe. Colour from whitish and pale grey to greyish-brown, darkening with age.

Stem

Cylindrical, 3–6 cm tall (up to 10 cm according to some descriptions), 1–3.5 cm thick (up to 4 cm), swollen or tapering at the base, sometimes off-centre. Whitish at first, later grey to brown; the surface is velvety or has appressed fibrils. No ring.

Flesh

Firm, dry, whitish to buff, becoming greyish-brown with age, brownish at the base of the stipe. Smell spicy, taste pleasant in young specimens; older ones may be somewhat bitter and fibrous. The raw flesh should not be tasted.

Spore print and spores

Spore print brown. Spores roundish, with numerous warts, 6–8 × 5–5.5 µm.

Habitat and distribution

Ecology. A terrestrial species, growing singly or in groups (sometimes in rings), in coniferous forests, mainly in montane and submontane spruce stands (according to some descriptions also under fir), on acidic and sandy soils, occasionally on calcareous ones. Descriptions give differing modes of nutrition (saprotroph or mycorrhizal).

Distribution. Widespread in Europe and North America, also recorded in Japan; specimens from the British Isles and the Netherlands are now assigned to S. squamosus. In Poland it is on the Red List of plants and fungi (category V – vulnerable), although in some areas it can be common. Until 9 October 2014 it was strictly protected in Poland; it is now not under species protection and is not on the list of fungi approved for sale in Poland.

Fruiting. In Europe from August to October; in North America from July to September, and on the west coast from September to December.

What can it be confused with?

• Sarcodon squamosus (pine scaly tooth) — Finer, less upturned scales and usually smaller fruiting bodies; grows under pines. Morphologically very similar, so the tree it grows under is the key feature.
• Hydnellum scabrosum (bitter tooth) — Smaller cap (up to 12 cm) with finer, appressed scales; flesh bitterish, with a blue-green tinge at the base of the stipe. Inedible. Protected in Poland (strict protection), not included in the Atlas — do not pick.
• Hydnellum joeides (violet tooth) — Also brown, but the flesh slowly turns violet when cut. Protected in Poland (strict protection), not included in the Atlas — do not pick.
• Sarcodon amarascens — Bitter and inedible; distinguished by a blue-black zone in the flesh.
• Strobilomyces strobilaceus (old man of the woods) — Similar from above, with a shaggy, scaly cap, but the underside consists of tubes with pores, not spines.
• Hydnellum species, protected Sarcodon (S. joeides, S. underwoodii, S. glaucopus, S. scabrosus) and Boletopsis grisea — Caution: protected species (strict protection in Poland), not included in the Atlas. Hydnellum species have tough, corky fruit bodies, often fused and growing around needles or twigs; the protected Sarcodon species are smaller, bitter, often with a bluish-green stem base; Boletopsis has pores instead of spines. If in doubt, do not pick.

Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.

Interesting facts

• Described by Carl Linnaeus in 1753 as Hydnum imbricatum; the epithet imbricatus means "tile-like".
• DNA analyses have shown that the form growing under pines is a separate species, Sarcodon squamosus; specimens from the British Isles are now assigned to it.
• Old fruiting bodies contain blue-green pigments, which are used in Norway for dyeing wool.
• In Bulgaria the dried mushroom is ground into aromatic mushroom flour, and in Korea an infusion is made from it.