Russula subnigricans
Russula subnigricans, known as Nisekurohatsu (Japanese), is a basidiomycete mushroom of the genus Russula found in China, Japan, and North America. It has been responsible for mushroom poisoning in Taiwan and Japan. The effect was a serious one, rhabdomyolysis. Several active agents have been isolated; one designated russuphelin A by researchers in Japan.