yellow bolete

The mushroom has a cushion-shaped to convex cap measuring 4–12 cm (1.6–4.7 in) wide. The cap color is bright yellow when young, fading to dull yellow or tan when mature, and usually develops orange or reddish discolorations. The pore surface is initially bright yellow before turning greenish yellow to brownish yellow. The stem is 4–12 cm (1.6–4.7 in) long by 2–5 cm (0.8–2.0 in) thick, and somewhat thicker near the base. Although it is usually not reticulate, the upper part of the stem may have reticulations. All parts of the mushroom stain blue to bluish black when injured. The stark color changes that occur over the lifespan of the fruit body led one author to suggest that "the mushroom's personal grooming skills go to hell in a handbasket". A variety N. pseudosulphureus var. pallidus, found in Nova Scotia, is pale yellow with a lighter colored olive spore print compared to the nominate variety.

Similar species. Orton compared the similar Neoboletus junquilleus, concluding that it could be distinguished from N. pseudosulphureus by the following features: red-orange pores near the stem (compared to completely yellow); red color in stem base (compared to yellow or brownish); and a red-punctate stem (compared to yellow-punctate).

The fungus is known from Europe, eastern North America, and Costa Rica, where it fruits on the ground in deciduous and mixed forests, usually in a mycorrhizal association with oak, but occasionally with pine. It was reported from Himachal Pradesh, India for the first time in 1993.