Black Tooth

Black Tooth is the darkest of the common Phellodon species, a genus of small, tough, stalked toothed fungi that grow directly from woodland soil. Caps are frequently fused into irregular clumps, and the whole fruiting body has the feel of dense felt or thin leather rather than mushroom flesh. Old material dries hard and persists on the forest floor long after fresh specimens have finished producing spores.

Phellodon belongs to the Thelephorales alongside Hydnellum and Sarcodon, but it is set apart by a single decisive character: white spores. Every other genus of stalked hydnoid in that order drops brown, warted spores, so a white print from a dark, corky, spine-bearing ground fungus points straight to Phellodon.

A second useful trait shared across the genus is a strong sweet smell resembling fenugreek or curry that develops as the fruiting body dries. In P. niger the combination of blue-black colouring, a duplex flesh structure and that drying odour makes the species reasonably distinctive.

Cap

Typically 3-8 cm across, flat to slightly depressed and very irregular in outline, with neighbouring caps often fusing into broad compound masses. The surface is velvety when young, later matted and roughened, and coloured blue-black to brown-black overall with a conspicuously paler whitish, grey or bluish-grey growing margin. Faint concentric zoning is often visible.

Spines

The underside carries short, crowded, decurrent spines 1-3 mm long, whitish to pale grey at first and ageing grey to grey-brown. Even in the darkest specimens the spines remain far paler than the cap, giving a strong contrast when the fungus is turned over.

Stipe

Short and stout, 1-4 cm tall, black to blue-black, densely felted or velvety, often with a thick spongy layer of matted mycelium and soil at the base that binds litter into a solid lump.

Flesh and spore print

The flesh is duplex, with a softer, spongier upper layer sitting on a hard, tough, black lower layer, best seen by cutting the fruiting body in half. It is bluish-black to black and faintly zoned. The spore print is white, and the spores are colourless, rounded and finely spiny. Dried specimens develop a strong sweet fenugreek-like odour.

This species fruits on the ground in woodland on poor, sandy, acidic soils, occurring under conifers such as pine and spruce and also under oak and beech on suitably impoverished ground. It favours shaded banks, track sides, sparse litter and mossy patches, and typically appears as clustered, partly fused groups rather than as scattered individuals.

The season runs from late summer through autumn, with blackened remains persisting into the following year. It is distributed across Europe, temperate and boreal Asia and North America, though as with other hydnoids the traditional broad species concept covers several closely related taxa. Populations have contracted across much of lowland Europe where soils have been enriched, and the genus is a focus of stipitate hydnoid conservation surveys.

Phellodon niger is ectomycorrhizal, forming root sheaths on conifers and on broadleaved partners such as oak and beech. The fungal mantle and its outward-radiating hyphae draw phosphorus, nitrogen and water from thin soils and pass them to the host in return for sugars, which is why the species is confined to standing woodland and cannot be found on dead wood.

The mycelium is perennial and slow to spread, producing dense mats that bind soil particles and litter around the base of the fruiting body. Established colonies persist for decades in the same place, and their strong sensitivity to nitrogen enrichment and soil compaction makes them reliable indicators of long-undisturbed woodland. The tough, persistent fruiting bodies release spores gradually over an extended period rather than in a single flush.

Phellodon melaleucus and Phellodon connatus are thinner and more delicately built, with paler grey-brown to whitish caps that are often white only at the centre, and with slimmer stalks; both share the white spore print. Woolly Tooth (Phellodon tomentosus) is much paler, cinnamon-brown, strongly zoned and funnel-shaped, and clearly thinner in section.

Dark Hydnellum species can look similar in the field, but they drop a brown spore print and have thick corky flesh without the sharply duplex soft-over-hard structure of Phellodon. Bankera species are paler and notably fleshier, with a soft, brittle texture rather than leathery toughness, though they too give a white print. Checking spore colour and slicing the fruiting body to look at the flesh layers separates all of these reliably.