The hedgehog mushroom (Hydnum repandum) is a highly regarded edible fungus sought by foragers globally. It is often called the “sweet tooth” or “wood hedgehog” due to its distinctive appearance. Unlike most familiar mushrooms, the hedgehog mushroom features small, soft spines or “teeth” on the underside of the cap. These unique, downward-pointing projections give the fungus its common name and serve as the spore-bearing surface.
Where Hedgehog Mushrooms Are Found Globally
Hydnum repandum is widely distributed across the temperate zones of the Northern Hemisphere, spanning North America, Europe, and parts of Asia. It is also recorded in Australia and Tasmania. In Europe, the species is common and is a well-known edible in countries like France, where it is called pied de mouton. The mushroom is broadly distributed across North America, occurring in the Pacific Northwest, the Rocky Mountains, and eastern regions.
Specific Habitat Requirements
The hedgehog mushroom is an ectomycorrhizal fungus, forming a mutually beneficial relationship with the roots of certain trees. This symbiotic association means it cannot be cultivated commercially and must be found in the wild. The fungus exchanges nutrients and water for carbohydrates produced by its host tree.
It is highly adaptable, thriving in deciduous, coniferous, and mixed woodlands. Common tree partners include hardwoods such as oak and beech, and conifers like pine and spruce. It can be found scattered individually, in groups, or sometimes forming “fairy rings” on the forest floor.
The mushroom prefers moist, shaded environments, often growing in leaf litter, humus layers, or mossy ground. It tends to favor slightly acidic soils. This species requires the organic matter and stable conditions provided by established forest ecosystems to fruit successfully.
When to Look for Hedgehog Mushrooms
The fruiting period for H. repandum begins in late summer and continues through late autumn. Timing varies by region, often extending from July through November in Eastern North America and August through December in Europe. In areas with mild winters, fruiting can continue well into the colder months.
Fruiting is commonly triggered by consistent rainfall following dry periods, combined with a drop in ambient temperature. This species tolerates cooler weather and is often one of the last edible mushrooms to appear before hard freezing. Foragers often find them emerging after chanterelle season has peaked, signaling a shift to late-season mushroom hunting.
Key Features for Positive Identification
The most defining characteristic is the presence of soft, brittle spines, or teeth, on the underside of the cap. These spines are typically white to pale cream or salmon-pink and are easily detached, differentiating them from the gills of other mushrooms. They may run slightly down the stem.
The cap of the hedgehog mushroom is usually irregular in shape, often wavy or lobed, and can range from five to 17 centimeters in diameter. Cap color is generally pale, varying from creamy white to pale yellowish-orange or pinkish buff. The stem is stout, firm, and often positioned off-center.