from August to October in conifer and beech woods, as well as heather (often close by sphagnum) in Scotland. It is mycorrhizal but non-selective in its hosts. Mushrooms appear from September to November in North America, and July and August in Alaska. It prefers acidic and sandy soils and avoids chalky ones, and may be found in the same habitats as bay bolete (Imleria badia), brown rollrim (Paxillus involutus), and chanterelles. It forms relationships with Scots pine (Pinus sylvestris). It is often found under Sitka spruce (Picea sitchensis), or near huckleberry in North America. In Alaska it grows with dwarf birch (Betula nana) and American dwarf birch (B. glandulosa). In Greenland, it grows in association with white birch (Betula pubescens). Edibility C. caperatus is a highly regarded edible mushroom with a mild to good flavour. It is said to mix well with stronger-flavoured fungi such as chanterelles, boletes, brittlegills or milk-caps. The mushroom can have a faintly bitter taste if eaten raw, but a pleasant nutty flavour when cooked. It can readily be dried for later use, such as adding to soups and stews. It is sold commercially in Finland, and is a popular target of foragers in many parts of Europe. The mushrooms are often found to be infested with maggots when picked. Mycologist David Arora recommends discarding the tough stipes. Radioactivity and environmental contamination The popularity of C. caperatus across Europe has led to safety concerns related to its propensity to accumulate contaminants. Fungi are very efficient at absorbing radioactive isotopes of caesium from the soil and naturally have trace amounts of the element. Caesium may take the place of potassium, which exists in high concentrations in mushrooms. C. caperatus bioaccumulates radioactive caesium 137Cs—a product of nuclear testing—much more than many other mushroom species. Levels dramatically rose after the 1986 Chernobyl disaster. This is a potential health issue as picking and eating wild mushrooms is a popular pastime in central and eastern Europe. Elevated 137Cs levels were also found in ruminants that eat mushrooms in Scandinavia in the 1990s. Mushrooms from Reggio Emilia in Italy were found to have raised levels of 134Cs. C. caperatus from various sites across Poland has also been found to contain increased levels of mercury. See also List of Cortinarius species References External links caperatus Fungi of Europe Fungi of North America Fungi of Asia Edible fungi Taxa named by Christiaan Hendrik Persoon