Aureoboletus wusangongii N.K. Zeng, H.Z. Qin, W.F. Lin & L.G. Hu, 2024

Aureoboletus wusangongii N.K. Zeng, H.Z. Qin, W.F. Lin & L.G. Hu , sp. nov. ( Figs. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

MycoBank: MB 855601

Etymology: Latin “ wusangongii ” is in honor of Wu Sangong, the originator of shiitake mushroom, who was the founder of the world's "cutting flowers" cultivation technique.

Diagnosis: Differs from other species of Aureoboletus by a stipe with distinctly coarse-lacerate reticulations, large basidiospores with longitudinal ridges, and subcutis pileipellis.

Holotype: CHINA. Zhejiang Province: Lishui City, Qingyuan County, Baishanzu National Forest Park , elev. 1200 m, 14 August 2023, N.K. Zeng 7864 ( FHMU7702 ). GenBank accession number: 28S = PQ278704, tef 1 = PQ274248, rpb 2 = PQ274250, ITS = PQ278706.

Basidiomata small, medium to large-sized. Pileus 4.3–11.8 cm diam, hemispherical, then convex; surface viscid when wet, densely covered with grayish-white (1B1) to white (1A1) fluffs, caducous, turning pale ochre (7A5–7B5) to light brown (6B5–6); margin straight to slightly incurved, entire; context 0.2–0.7 cm thick in the center of the pileus, white (1A1) to pinkish (6A2), unchanging in color when injured. Hymenophore poroid, depressed around apex of stipe; pores angular to subround, light yellow (1A3) to grayish yellow (30A3–4), or pale yellowish green (30A5), unchanging in color when injured; tubes 0.3–1 cm in length, light yellow (1A3–4), unchanging in color when injured. Stipe 9.3–13 × 1.2–1.7 cm, central, solid, subcylindrical; surface ochre (7B5–7B6) to light reddish-brown (7A3–4), with distinctly coarse-lacerate reticulations; context yellowish white (2A3), unchanging in color when injured. Basal mycelium white (1A1). Odor indistinct.

Basidiospores [100/5/4] 15–16.24–17.5 (–18) × 7–8.33–9 (–10) μm, Q = 1.78–2.13 (–2.29), Qm = 1.96 ± 0.12, yellow in KOH, elongate to cylindrical, slightly thick-walled (0.8–1.5 μm), with longitudinal ridges, 3–5 ridges visible in lateral view, projecting 0.5–2.5 μm wide; ridges continuous or forked, cleft at the apex, lacking cross-striations on the ridges observed under the light microscope. Basidia 37–50 × 13–17 μm, subclavatet, slightly thick-walled (0.5–1 μm), 4-spored, colorless to yellowish in KOH; sterigmata 2–7 μm in length. Hymenophoral trama composed of thin to slightly thick-walled (up to 0.5 μm) hyphae, 4–15 μm wide, colorless to yellowish in KOH. Pleurocystidia 60–83 × 10–17 μm, abundant, subfusiform, slightly thick-walled (up to 1 μm), colorless to yellowish in KOH, no encrustations. Cheilocystidia 58–73 × 14–20 μm, abundant, subfusiform, slightly thick-walled (up to 1 μm), colorless in KOH, no encrustations. Pileipellis a subcutis 140–270 μm thick, composed of slightly thick-walled (up to 1 μm) hyphae, 5–11 μm wide, colorless to yellowish in KOH; terminal cells 35–93 × 6–11 μm, clavate to cylindrical. Pileal trama composed of slightly thick-walled (up to 1 μm) hyphae, 4–19 μm wide, colorless in KOH. Stipitipellis a trichodermlike structure 93–170 μm thick, composed of slightly thick-walled (up to 1 μm) hyphae, 4–11.5 μm wide, colorless to yellowish in KOH; terminal cells 40–52 × 6–10 μm, subclavate to subfusiform. Stipe trama composed of parallel hyphae, slightly thick-walled (0.5–1 μm), 5–18 μm wide, subcylindrical, colorless in KOH. Clamp connections absent in all tissues.

Habitat: Solitary or gregarious on the ground in forests dominated by fagaceous trees. Known distribution: Eastern China (Zhejiang Province). Additional specimens examined: CHINA. Zhejiang Province: Lishui City, Qingyuan County, Baishanzu National

Forest Park, elev. 1200 m, 13 August 2023, N.K. Zeng 7856 ( FHMU7701 ) ; Lishui City, Qingyuan County, Zuoxi

Town , Yinjiang Village, elev. 1100 m, 18 August 2024, L.G. Hu 20240818002 ( FHMU7730 ) ; same location, elev. 900

m, 19 August 2024, N.K. Zeng10189 (FHMU7731).