Depressed Hedgehog Identification Guide

The Ground You Are Kneeling On

Depressed Hedgehog is a small fungus and you will usually be crouched down to see it properly. The habitat is distinctive: damp to boggy conifer forest, often with hemlock or spruce overhead, and a floor of deep moss — frequently sphagnum — rather than bare litter. It also appears along mossy ditch banks, on the raised hummocks in cedar swamps, and around the edges of forest bogs.

The first impression is a small apricot-orange button pushed up through moss, sometimes barely clearing the surface, with the moss still gripping the lower half of the stalk. The cap is matte and dry, not shiny, and the colour is soft — pale orange, orange-buff, salmon-tan — with no red or brown flush. Often you spot one and then, once your eye adjusts, another dozen appear across a few square metres, scattered singly rather than clustered, because this is an ectomycorrhizal fungus fruiting along a root system.

Two things you should notice within the first few seconds: the middle of the cap is sunk into a distinct little pit, and the underside is not smooth or gilled but bristly.

The Cap

Measure it. The cap is typically 2 to 6 cm across, occasionally slightly more, which is small for a hedgehog. It starts convex or flat with an inrolled margin, and the centre then sinks progressively until a mature cap is shallowly funnel-shaped with a sharply defined navel-like dimple at the very middle. In fully developed specimens this depression is deep enough to be obvious in profile and sometimes runs down as a small hollow into the top of the stalk. That navel is the character the species is named for and the one you should photograph.

The surface is dry, matte and finely felted or suede-like, never viscid. The colour is pale orange to orange-buff or dull salmon, generally even across the cap but sometimes paler at the edge. The margin is thin, often wavy or lobed and irregular rather than round, and it commonly splits or cracks in dry weather. Older caps become somewhat brittle and their edges tatter.

The Spore-Bearing Surface

Turn it over. Instead of gills, plates, pores or wrinkles, the underside is covered in a dense pile of soft downward-pointing spines, like the nap of a brush. This is the character that places the collection instantly.

Look closely. The spines are 2 to 6 mm long, slender, cylindrical to tapered, crowded, and coloured white to pale cream or a faint orange-buff — always paler than the cap. They are fragile: brush a fingertip across them and they snap off easily, leaving small bald patches. The spine layer runs down onto the top of the stalk to a noticeable degree, so the boundary between cap underside and stipe is a sloping transition rather than a sharp line. On a mature cap the spines are shortest at the margin and longest toward the middle.

Stipe, Base and Flesh

The stalk is 3 to 7 cm long and slim, roughly 0.5 to 1.5 cm thick, more or less cylindrical or slightly swollen below, sometimes off-centre where the fruitbody has grown up against a stem of moss. It is whitish to pale orange, dry, smooth to very finely downy, and stuffed with soft flesh that often becomes hollow with age. There is no ring and no volva; the base simply narrows into the moss with pale mycelial threads and moss fragments attached.

Handle it and then look again after a few minutes. Bruised areas — the stalk where you gripped it, the cap where you pressed it — slowly discolour to a deeper orange or orange-brown. The change is gradual, over several minutes rather than seconds, and it is a supporting character.

Cut the fruitbody vertically. The flesh is white to very pale cream, brittle in the cap, softer and more fibrous in the stalk, and it slowly develops orange-buff to yellow-brown marbling on the cut surface as it dries. It does not blue and it does not turn green.

Spore Print

Because the spore surface is spiny, print the specimen the same way you would a gilled cap: trim the stalk close, lay the cap spine-side down on white paper under a cover, and give it four to eight hours. The deposit is white to faintly cream. Read it against a dark background or by tilting it in the light.

Do this on a mature cap; young hedgehogs release spores sparingly and may leave almost nothing. Under a microscope the spores are broadly ellipsoid to subglobose and smooth, without ornamentation, which is another point of separation from the tooth fungi with brown, warted spores.

Substrate and Season

Soil and moss, always — this species is ectomycorrhizal with conifers and fruits from ground, never from wood. Look for it in wet coniferous woods, hemlock stands, spruce bogs, cedar swamps and mossy stream margins, chiefly across northern and montane North America. The season runs from late summer into autumn and sometimes into early winter where conditions stay mild and damp.

Separating It From Look-alikes on Structure Alone

Hydnum repandum, the larger common hedgehog, is the main comparison. It is a much bigger, thicker, sturdier fungus with a cap commonly 5 to 15 cm across, a stouter stalk, and a cap that is convex to flat or only irregularly depressed — it never develops a clean, sharply defined navel. Its colour is usually a paler cream-buff to pale orange rather than the more saturated apricot tone here. Size, thickness and the absence of a true umbilicus separate them.

Hydnum rufescens and its relatives are closer in size and colour, but the cap is plane to gently depressed rather than navelled, the fruitbody is a little more slender and evenly orange, and the spines tend not to run so far down the stalk. Microscopy of spore dimensions is the reliable arbiter, since these species overlap in the field.

Hydnum albidum is whitish to pale cream with only faint orange tones and a flat to slightly depressed cap.

Chanterelles, Cantharellus, are the classic confusion at a glance because the colour and the funnel shape are similar. Turn the fruitbody over: chanterelles have blunt, forking, gill-like ridges that are part of the flesh, not free-hanging spines. No chanterelle has teeth.

Sarcodon and Hydnellum species also carry spines, but they are altogether different in build: tough, corky or woody flesh, dark brown to grey-purple scaly caps, often fused into masses, and brown warted spores.

Auriscalpium vulgare has spines but a thin lateral stalk and grows out of buried pine cones.

Hericium species have spines with no cap at all, hanging from a branched or cushion-like mass on wood.