A common mushroom of deciduous and coniferous woods and grassy areas in late summer and autumn, "Paxillus involutus" forms ectomycorrhizal relationships with a broad range of tree species. These benefit from the symbiosis as the fungus reduces their intake of heavy metals and increases resistance to pathogens such as "Fusarium oxysporum". Previously considered edible and eaten widely in Eastern and Central Europe, it has since been found to be dangerously poisonous, after being responsible for the death of German mycologist Julius Schäffer in 1944. It had been recognized as causing gastric upsets when eaten raw, but was more recently found to cause potentially fatal autoimmune hemolysis, even in those who had consumed the mushroom for years without any other ill effects. An antigen in the mushroom triggers the immune system to attack red blood cells. Serious and commonly fatal complications include acute kidney injury, shock, acute respiratory failure, and disseminated intravascular coagulation.