''Porphyrellus sordidus'' is a bolete fungus in the family Boletaceae. It was originally described in 1874 by

Charles Christopher Frost Charles Christopher Frost (November 11, 1805 – March 16, 1880) was an American mycologist. He described several species of fungi from the New England area of the United States. In one paper, Frost described 22 new species of boletes, and he wa ...

as a species of '' Boletus''.

Fruit bodies The sporocarp (also known as fruiting body, fruit body or fruitbody) of fungi is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne. The fruitbody is part of the sexual phase of a fungal life cyc ...

of the fungus have a convex to flattened cap measuring in diameter. The brownish cap surface is initially

tomentose Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

to felt-like, but develops cracks in age. All parts of the mushrooms bruise dark blue to greenish when injured. The spore print is reddish brown; spores are smooth, roughly elliptical, and measure 10–14 by 4–6

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

. The bolete is found in North America, where it grows on the ground under

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

s and

conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...

s. Its edibility was recently unknown, but it is now considered inedible.

References

sordidus Inedible fungi Fungi described in 1874 Fungi of North America Fungus species {{Boletales-stub