Boletus fibrillosus

Boletus fibrillosus is a basidiomycete fungus of the genus Boletus found in western North America. The fruiting bodies are found in mixed coastal forests in the fall. The cap is up to 17 cm wide, buff to brown to dark brown in color, and has a wrinkled to finely fibrous texture. The tubes are yellow, while the flesh is white to buff and does not stain when cut. The stem is yellow at the top, brown otherwise, and has a reticulate texture. The holotype was collected in Mendocino County, California.

Phylogenetic analysis has shown B. fibrillosus as a member of a clade, or closely related group, with B. pinophilus, B. regineus, B. rex-veris, B. subcaerulescens, and Gastroboletus subalpinus.