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Summer 2021


Mycorrhizal with hardwoods and found where conifers are present; widely found in eastern North America as well as the Midwest; growing in summer and fall; most often scattered or solitary and sometimes gregarious. Smooth to velvety, convex, brown cap; cap flesh stains blue; pore surface bright yellow and sponge-like with very small pores, stains blue when first affected then turns brown; finely reticulate stipe that is light yellow, becoming scarlet red towards the base; when exposed to KOH cap turns bright red and inner flesh turns reddish-brown; taste not distinctive, slightly sour. Butyriboletus is a new genus within the family Boletaceae established in 2014 (Arora, 2014); the species was formerly known as Boletus speciosus var. brunneus. Morphologically similar to Butyriboletus peckii which is characterized by smaller reticulation on the stipe as well as a yellow coloration that turns red higher up the stipe. ID number:


Location: East Brook Valley, Walton, NY (PC - Pinus Creek)

Butryiboletus brunneus