High Quality Content by WIKIPEDIA articles! Boletus frostii, commonly known as Frost`s bolete or the apple bolete, is a bolete mushroom 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 its cap. The fruit bodies may 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 are the amber drops exuded on the pore surface.