(Boletus satanas), a hymenomycetous mushroom of the family Boletaceae. The fruiting body is large and fleshy, and the cap reaches 20 cm in diameter and 5 cm in thickness. The thick stalk, which is swollen at the base and has a network of thin red veins at the top, is yellow, with a reddish zone in the middle. The cap is yellow or light gray on top; the tubular layer is red. The pale yellow flesh turns red or dark blue when broken and has an odor of raw potato. Satan’s mushroom is quite rare. It grows in carbonate soils in deciduous forests of the southern European part of the USSR. The mushroom is often considered poisonous.