Boletus Amygdalinus

This species may be specific to California, growing in late Autumn under oak trees. It shares some of the same macroscopic properties as Boletus satanis, including red pores and blue staining when cut. The stem can be quite wide, but never bulbous like B. satanis. It is almost certainly poisonous, at least emetic. One should avoid eating any red pored, blue staining bolete.