Hydnum repandum, the hedgehog mushroom, is a fungus of the family Hydnaceae. First described by Carl Linnaeus in 1753, it is the type species of its genus. The cap is dry, colored yellow to light orange to brown, and often develops an irregular shape, especially when crowded. The mushrooms are characterized by spore-bearing structures—in the form of spines rather than gills—which hang down from the underside of the cap. The mushroom tissue is white with a pleasant odor and a spicy or bitter taste. All parts of the mushroom stain orange with age or when bruised. A mycorrhizal fungus, H. repandum is broadly distributed in Europe, Asia and western North America, where it fruits singly or in close groups in coniferous or deciduous woodland. This is a choice edible species, although mature specimens can develop a bitter taste. The mushrooms are sold in local markets of Europe and Canada. (Full article...)