About Porphyrellus sordidus (Frost) Snell
Porphyrellus sordidus (Frost) Snell is a bolete fungus that belongs to the family Boletaceae. It was first formally described in 1874 by Charles Christopher Frost, who originally classified it as a species of the genus Boletus. The fruit bodies of this fungus have caps that range from convex to flattened in shape, with a diameter between 4.5 and 13 cm (1.8 to 5.1 inches). The cap surface is brownish, with a texture that is initially tomentose or felt-like, and develops cracks as it ages. When any part of the mushroom is injured, it bruises to a dark blue or greenish color. The spore print of Porphyrellus sordidus is reddish brown. Its individual spores are smooth, roughly elliptical in shape, and measure 10–14 by 4–6 micrometers. This bolete fungus occurs in North America, where it grows on the ground in association with oaks and conifers. While its edibility was unknown until recently, it is now classified as inedible.