Boletus frostii, commonly known as Frost’s bolete or the apple bolete, is a bolete fungus first described scientifically in 1874. A member of the Boletaceae family, the mushrooms produced by the fungus have tubes and pores instead of gills on the underside of their caps. Boletus frostii is distributed in the eastern United States from Maine to Georgia and Arizona, and south to Mexico and Costa Rica. A mycorrhizal species, its fruit bodies are typically found growing near hardwood trees, especially oak.
Boletus frostii mushrooms can be recognized by their dark red sticky caps, the red pores, the network-like pattern of the stem, and the bluing reaction to tissue injury. Another characteristic of young, moist fruit bodies is the amber-colored drops exuded on the pore surface. Although the mushrooms are considered edible, they are generally not recommended for consumption because of the risk of confusion with other poisonous red-pored, blue-bruising boletes. B. frostii may be distinguished from other superficially similar red-capped boletes by differences in distribution, associated tree species, bluing reaction, or morphology.