Name in North American Boletes: Boletus inedulis
- Genus 2: Xercomus
Tells: Bitter, whitish-yellow cap flesh stains blue. Yellow pores darken w/age & stain blue. Netted stem is yellow on top, red going down, w/dark-staining base.
Other Information: Light gray cap browns, cracks, & fissures w/age. Likes oak & hemlock. A European version (B. radicans) has been reported in the Northeast but is disputed. Radicans cap is pale white/gray that turns brown, with lemon yellow pores when young, and a bulbous stem that is pale on the bottom and bright yellow on the top.
Science Notes: DNA testing moved this mushroom from Boletus to a newly erected genus called “Caloboletus”.
Edibility: Avoid. Too bitter to eat.
- NH4OH (Ammonia): No reaction.
- KOH: Cap surface turns pale orange. Cap flesh turns deep orange.
- FeSO4 (Iron Salts): Cap flesh does not react.