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Description type:Original description 
Description:Pileus (Figs. 1, 2) 60–140 (–170) mm in diam, at first hemispherical, expanding to broadly convex, with slightly appendiculate, straight margin; surface dry or sometimes subviscid when wet, mostly entirely covered with small, dark brown (7F5–6F5) to reddish brown (8E4–5), matted scales, at times felty-tomentose to velvety overall from the first, ground color light brown (6D4–5) to brown (6E5) at first, blond (4C4), brownish orange (5C5–6C5) at maturity overall, unchanging when bruised. Flesh up to 25 (–30) mm thick at the center of the pileus, becoming very thin toward the margin, pale yellow (4E3), at times stained with greyish red (10C5) to brownish red (10C6) at the base of stipe and right beneath the pileus and the stipe surface, gradually changing to blue when cut, yellow (3A4) or orange (5A6) in KOH, negative in NH4OH, negative or bluish in guaiac, brownish in phenol, inamyloid in Melzer’s reagent; taste bitter, odor indistinct. Stipe (Fig. 1) 65–130 — 15–35 mm, subcylindrical or somewhat thickened toward the base, central, terete, solid; surface dry, red (11A7 to 11B7–8) downward, greyish yellow (4B6) at the apex, densely covered overall with reddish brown (8E5–9D5) to greyish red (10D4) pruina, finely but conspicuously reticulated over the upper half by a thin-veined, concolorous reticulum with meshes subequal (above) to longitudinally elongated (below), gradually changing to blue where handled; basal mycelium yellowish white (1A2) to pale yellow (1A3). Tubes 7–15(–19) mm deep, depressed around the stipe, light yellow (4A4–5) at first, becoming greyish yellow (2B5–6) with age, instantly changing to blue when exposed; pores 2–3 per mm, subcircular, concolorous with the tubes, sometimes with reddish stains, instantly changing to blue when bruised. Spore print olive (2E4).
Basidiospores (Fig. 7) (11.3–)13.6–15.2(–16.4) — (4.6–)5.4–6.0(–6.5) µm (n = 266, mean length = 14.37 ± 0.78, mean width = 5.69 ± 0.28, Q = (2.0–)2.4–2.7(–3.3), mean Q = 2.53 ± 0.17), inequilateral with a shallow suprahilar depression in profile, subfusoid in face view, with a rounded apex, smooth, greenish grey (1B2) in dried condition, greenish grey (1B2) in water, greyish yellow (4B5) in KOH, inamyloid or infrequently weakly dextrinoid, with slightly thickened walls (up to 0.5 µm). Basidia (Fig. 6) (24.2–)26.6–33.2(–38.9) — (10.8–)11.6–13.0(–14.4) µm (n = 75), clavate, 4–spored; sterigmata (3.0–)3.5–4.7(–5.3) — (1.5–)1.8–2.4(–3.0) µm. Basidioles clavate. Cheilocystidia (Fig. 4) abundant, forming a compact sterile edge, (18.6–)22.8–32.2(–37.4) — (4.4–)5.7–7.9(–10.2 ) µm (n = 94, mean length = 27.49 ± 4.67, mean width = 6.78 ± 1.12), narrowly fusoid-ventricose to ventricose-rostrate with an obtuse apex, smooth, hyaline in water and KOH, inamyloid, thin-walled. Pleurocystidia (Fig. 5) scattered, (35.3–)38.8–56.1(–77.6) — (6.3–)7.3–10.2(–14.5) µm (n = 49, mean length = 47.43 ± 8.63, mean width = 8.77 ± 1.47), similar in shape to cheilocystidia. Hymenophoral trama bilateral-divergent of the Boletus-subtype; elements 3.0–4.4 µm wide in a mediostratum, 6.0–7.9 µm wide in lateral strata, cylindrical, smooth, colorless in water and KOH, thin-walled. Pileipellis (Fig. 3) made up of loosely entangled hyphal ends; constituent hyphae of the scales 5.9–9.4 µm wide, cylindrical, spirally encrusted with brownish (5C4–5) granular pigment (in water) that are not dissolved in KOH, inamyloid, reddish (6C8) in KOH, thin-walled. Pileitrama of cylindrical, loosely interwoven hyphae 5.3–9.6 µm wide, smooth, colorless in water and KOH, inamyloid or weakly dextrinoid, thin-walled. Stipitipellis consisting of tufts of caulocystidia and infrequent caulobasidia; caulocystidia (Fig. 8) at the upper portion (24.4–)30.0–54.2(–100.4) — (4.1–)6.4–8.9(–12.0) µm (n = 134, mean length = 42.11 ± 12.08, mean width = 7.69 ± 1.25), subclavate or narrowly fusoid-ventricose to ventricose-rostrate, at times subcylindrical, reddish (9C7) in water, yellowish (3A3) in KOH, inamyloid; caulocystidia (Fig. 10) at the lower portion (41.1–)50.1–99.6(–148.6) — (4.7–)6.0–7.8(–8.9) µm (n = 38, mean length = 74.87 ± 24.77, mean width = 6.90 ± 0.93), subcylindrical, occasionally 1–2 septate, brownish (5C4) in KOH; caulobasidia (Fig. 9) (26.7–)31.4–40.2(–45.2) — (10.1–)10.6–12.0(–12.9) µm, 2–4–spored, yellowish (3A3) in KOH, inamyloid. Stipe trama composed of longitudinally running, cylindrical cells (4.7–)6.3–10.8(–15.0) µm wide, unbranched, smooth, colorless in water, hyaline in KOH, dextrinoid, thin-walled. Clamp connections absent.
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