Boletus impolitus Fr. syn. Xerocomus impolitus (Fr.) Quél Fahler Röhrling Iodine Bolete Cap 5–15cm, clay coloured, sometimes with tawny or olive tints with a pale grey hoariness at first, dry, slightly velvety, then smooth. Stem 60–100 x 30–50mm, robust, straw-coloured at apex, darker brown towards the base. Flesh pale lemon-yellow with deeper yellow region above the pores, becoming faintly pink or very rarely faintly blue after some time on cutting. Taste mild, smell of iodoform in stem base. Tubes lemon-yellow then lemon-chrome. Pores small, similarly coloured. Spore print olivaceous snuff-brown. Spores subfusiform, 10–14 x 4.5–5.5µ. Habitat on rides in broad-leaved woods, particularly oak and often on clay soils. Season early summer to autumn. Rare. Edible. (Two forms illustrated.) Distribution, America and Europe.