Boletus pulverulentus Opatowski Cap 4-10cm across, broadly convex; deep yellow-brown to blackish brown, sometimes with reddish hues; subtomentose to dull, dry, or glabrous, tacky when moist. Tubes yellow, but instantly deep blue when cut. Pores large and angular; lemon yellow, instantly deep blue when touched. Stem 40-80 x 10-30mm, equal to tapering below; bright yellow-orange on apex, reddish brown below, turns instantly blue-black when handled; surface pruinose. Flesh soft; yellow then deep blue to almost black when cut. Odor not distinctive. Taste not distinctive. Spores subfusiform, 11-14(15) x 4.5-6µ. Deposit olive-brown. Habitat in grassy oak woods and in garden lawns, particularly on slopes and banks. Often common. Found throughout northeastern North America. Season July-August. Edible. Comment One of the most easily identifiable boletes, with its instant and very deep blue color change of all parts. Ammonia on the cap cuticle gives a fleeting green coloration.