Suillellus amygdalinus

Suillellus amygdalinus (formerly Boletus amygdalinus) is a fungus of the bolete family found in western North America. The fruit bodies, or mushrooms, are characterized by their thick, red to brown caps, red pores, and the strong bluing reaction observed when the mushroom tissue is injured or cut.

The cap can reach diameters of up to 12 cm (4.7 in) and the stipe 9 cm (3.5 in) long by 3 cm (1.2 in) thick at maturity. Other similar red-pored, bluing boletes from North America, including Rubroboletus eastwoodiae, Boletus luridiformis, and B. subvelutipes, can be distinguished from S. amygdalinus either by the color of the cap, the degree of reticulation (a network of raised ridges) on the stipe, or by location.

This mushroom has been found in manzanita and madrone woodlands of central California north to southern Oregon. The edibility of the mushroom is unknown, but it may be poisonous.