Medulla K+ yellow to red. The first photo is taken in my back yard because I forgot to take a natural photo, but it was on a large fallen limb of Fraxinus in a successional hardwood forest, mostly ash, poplars and red maples. Notice the lack of obvious or reticulate maculae and the broad rhizineless region on the undersurface.

on rock in the open; underside white; no soredia or isidia; many white maculae; cortex K+ yellow; medulla white and K- (next to last photo shows piece of thallus with large patch of cortex removed in lower left; last photo same after application of K to region with cortex (yellow spot) and to exposed medulla ( no reaction)

Found growing on the ground in a deciduous forest, few feet from a stream. Smooth and dry cap, not sticky.

I thought it was a standard yellow-pored bolete when I saw the cap and poked it with my shoe, so I ended up freaking out when I saw its pores and realized I broke the cap of a bolete I’ve actually never seen before -_-

Going off of a key I found on the internet, it seems to match the description of Boletus rubroflammeus?

Edit: Found another one in the same spot (8/20/2024), didn’t break it this time lol

Recommended by Doug Danforth to be labeled as Progomphus cf. lambertoi for the moment, although more specimens are needed to determine relationship between P. cf. lambertoi from Yecora and Alamos areas of Sonora, P. lambertoi populations from further south, and P. belyshevi. These may involve one or more species, per discussion and examination of specimens and photos by Rosser Garrison, Dennis Paulson, Rich Bailowitz, Doug Danforth, and Pierre Deviche (fide Pierre Deviche).