Ear-pick Fungus

The Ear-pick Fungus is one of the most singular small fungi in the northern woods. Barely two centimetres across, it consists of a dark, hairy, kidney-shaped cap carried on a thin stalk attached at the cap's edge rather than its centre, so the whole thing resembles a tiny spoon or the ear-scoop tool that gives it its name. Underneath the cap are fine spines, marking it as a hydnoid fungus.

Auriscalpium is placed in the Russulales, the same order as Hericium and the brittle-gilled Russula species, and shares their amyloid, ornamented spores. The genus is small and its members are all specialists on woody, resistant substrates, mostly conifer cones.

What secures its identity in the field is the substrate. No other stalked toothed fungus fruits from pine cones, and once you learn to look at cones lying under Scots pine or other conifers, the species turns out to be far more common than its size suggests. It also has a remarkably long season, appearing in almost any month and persisting in dry, leathery condition through winter.

Cap

Small, only 0.5-2 cm across, kidney-shaped to almost circular but attached at one side, convex and often slightly notched. The surface is dark brown to blackish-brown and densely covered in coarse hairs, giving a distinctly shaggy or velvety look under a hand lens. The margin is often paler and fringed with hairs.

Spines

The underside carries fine, crowded, pointed spines 1-3 mm long, whitish to pale grey when young and darkening through grey-brown to purplish-brown as spores mature. They hang vertically because the cap is held horizontally on its side stalk.

Stipe

Slender and wiry, 2-6 cm tall and only 1-2 mm thick, dark brown to blackish and densely hairy like the cap, attached to the edge of the cap rather than its centre. The base is inserted directly into a cone scale or into the cone axis.

Flesh and spore print

The flesh is very thin, tough and leathery, brown, and does not change colour on cutting. The spore print is white; spores are small, broadly ellipsoid, minutely spiny and amyloid, staining blue-grey in iodine reagents.

This fungus is a cone specialist. It fruits from fallen cones of pine, especially Scots pine, and from cones of spruce and other conifers in some regions. Cones may be lying on the surface, half buried in litter or completely covered by needle debris, in which case the wiry stalk emerges through the litter with no visible substrate, and digging is needed to reveal the cone below.

Fruiting bodies can be found in every month of the year, with peaks in autumn and early winter, and old fruiting bodies persist in dry leathery form for a long time. The species is widespread throughout the Northern Hemisphere wherever conifers grow, occurring across Europe, Asia and North America, and it is often abundant in plantation as well as natural pine woodland.

Auriscalpium vulgare is a saprotroph with a narrow substrate range, decomposing the tough lignified scales and axis of conifer cones. Cones are a difficult resource, rich in lignin and resins and poor in easily available nutrients, so relatively few fungi can exploit them. By specialising, this species avoids competition with the broad-spectrum wood and litter decomposers that dominate the forest floor.

Its role is a small but real part of nutrient recycling in conifer forest, returning carbon and minerals locked in cones to the soil. A single cone may support one or several fruiting bodies over successive seasons as the mycelium works through it. Cones colonised by this fungus are typically softened and darkened, and they break down noticeably faster than uncolonised ones nearby.

There is essentially nothing else with the same combination of features, but several other small fungi share the cone habitat. Strobilurus tenacellus and Baeospora myosura both fruit from buried pine and spruce cones and have slender stalks of similar length, yet both are pale-capped agarics with true gills and centrally attached stalks, not spines on a lateral stalk. Mycena species on litter are likewise gilled with central stalks.

Among toothed fungi, Hydnum and Hydnellum species are far larger, grow from soil, and have central or thick stalks. The dark hairy cap, lateral wiry stalk, tiny size and pine-cone substrate together make the Ear-pick Fungus unmistakable once it has been seen.