Leccinum duriusculum (Schulz.) Sing. syn. Boletus duriusculus Schulz. Pappelröhrling Nyárfa érdestinóru (-tinóru) Cèpe rude des peupliers Slate Bolete. Cap 6–15cm, light cinnamon-buff, slightly downy to somewhat stippled, becoming smoother with age, cuticle overhanging tubes. Stem 80–140 x 20–35mm, white at apex, buff towards the base, ornamented with black or brown-black scales, often tinged blue-green near the base. Flesh firm, white, pink or peach in the cap, vinaceous grey in the stem apex and with touches of blue-green fading brownish in the stem base, finally blotched blackish throughout. Taste and smell not distinctive. Tubes whitish then pale yellowish. Pores small, round, whitish bruising olive brown. Spore print snuff-brown. Spores subfusiform, 14.5–16 x 4.5–6um. Habitat with aspens. Season summer to late autumn. Rare. Edible. Distribution, America and Europe.