Leccinellum rugosiceps

It has firm flesh that stains initially pinkish to reddish and then to grayish or blackish when injured.

The species was first described scientifically in 1904 by American mycologist Charles Horton Peck as Boletus rugosiceps.

[8] The specific epithet rugosiceps, which is derived from the Latin roots for "rough" and "head",[9] refers to its wrinkled cap.

[11] The cap tends to undergo significant color changes throughout its development—first bright yellow, then dark brown, then finally pale tan—which may make it difficult to identify in the field.

[12] The flesh is white to pale yellow, and it stains reddish to burgundy when cut or bruised.

A drop of dilute potassium hydroxide (KOH) turns the cap surface red, and the flesh yellowish to orangish.

It generally has a darker cap, paler scabers, and somewhat wider spores, although these characteristics are variable.

[12] In his original species description, Charles Peck noted that L. rugosiceps grew with Hemileccinum rubropunctum, "from which it is easily separated by its dry pileus, smaller tubes and stouter stem.

"[4] An edible species, Leccinellum rugosiceps mushrooms have been described variously as "great",[12] and "of poor quality".

In eastern North America, pin oak (Quercus palustris) is a frequent host.

[11] A Chinese study evaluating the concentrations of heavy metals in boletes found that in L. rugosiceps fruitbodies, the levels of cadmium, zinc, copper, and mercury exceeded that of national safety standards for edible fungi.

[19] The bolete is found from eastern Canada south to Florida and Mississippi, west to Michigan in the United States.

Taiwanese specimens tend to have slightly smaller spores (10–16 by 4–5 μm) than those from mainland China or from America.

Spores are smooth and spindle shaped.
Leccinellum crocipodium is a lookalike
A collection of L. rugosiceps fruitbodies