COMMON NAME: Red-mouth Bolete.

CAP: (6-13 cm) wide, convex, becoming broadly convex to nearly flat; surface dry, finely velvety when young, occasionally finely cracked with age, color variable, cinnamon-brown to yellow-brown, reddish brown, or reddish orange to orange-yellow, quickly staining blue to blue-black when bruised; flesh bright yellow, quickly staining dark blue when cut or bruised; odor not distinctive; taste mild to slightly acidic.

PORE SURFACE: red or red-orange to orange when fresh, duller in age, quickly staining dark blue to blackish when cut or bruised; pores circular, 2 per mm.

STALK: (3-10 cm) long, (1-2 cm) thick, nearly equal, solid, punctate with red dots and points, not reticulate, quickly staining dark blue to blackish when bruised; with short, stiff, dark red hairs at the base on mature specimens (immature specimens often have yellow hairs that become dark red in age); partial veil and ring absent.

SPORE PRINT: dark olive-brown.

MICROSCOPIC FEATURES: spores 13-18 x 5-6.5 μm, fusoid-subventricose, smooth, pale brown.

FRUITING: solitary to scattered on the ground under hardwoods, especially oak; June-September; fairly common.

EDIBILITY: poisonous.

COMMENTS: this mushroom causes mild to severe gastrointestinal upset when eaten. Peck's original description of this species states that the flesh is whitish. Although Smith and Thiers report this description in The Boletes of Michigan, they then describe Michigan specimens as having bright yellow flesh. Several field guides state that the flesh of Boletus subvelutipes is yellow. In his recent compendium, The Boletes of North America, Ernst Both notes Peck's description of the flesh of Boletus subvelutipes as whitish. According to him, a possible explanation for this confusion is that the flesh, which is initially yellow and stains blue instantly, slowly fades to white.

From Mushrooms of Northeastern North America Alan E. Bessette, Arleen R. Bessette, & David W. Fischer  Copright © 1997 Syracuse University, ISBN 0-8156-0388-6