Pseudoaustroboletus valens

Pseudoaustroboletus valens (Corner) Yan C. Li & Zhu L. Yang 2014, in Li et al., Mycological Progress 13(4), 1209 (2014).

            Basionym: Boletus valens Corner 1972

Diagnosis: Basidiomata 5–8 cm broad, small to medium-sized. Pileus dark grey or pale fuscous grey to greyish white, paler on expansion, subhemispherical or hemispherical to applanate, dry, not viscid when wet; glabrous, with radially arranged filamentous squamules when aged; context in pileus white to pallid, unchanged in color when injured. Hymenophore adnate to depressed around apex of the stipe, pallid to pale pinkish or pinkish to pink, unchanged in color when injured; tubes and pores concolorous, tubes up to 1.5 cm long and pores up to 0.1 cm in diameter, unchanging in color when bruised. Stipe 9–12×1.5–2.5 cm, central, subcylindrical, sometimes enlarge downwards, reticulate with elongate meshes up to 0.5 mm in height, wholly pallid to white or whitish; context in stipe white to whitish unchanging in color when bruised, but some collections occasionally with yellow to yellowish or pinkish stains at the base of stipe on injury; mycelia on the base of stipe white. Taste slightly sour.

Basidia 27–32×8.5–12 μm, clavate, hyaline to light yellowish in KOH, thin-walled, four-spored, occasionally two-spored. Basidiospores [240/12/12] (11.5) 12–15 (16.0)×(4.0) 4.5–5.5 (6.0) μm, [Q=(2.18) 2.33–3.18 (3.50), Qm=2.69± 0.21], boletoid, slightly thick-walled (up to 0.5 μm in thickness), subhyaline to light olivaceous in KOH and yellowish brown in Melzer ’s reagent, smooth under SEM. Pleurocystidia and cheilocystidia 22–62×6.5–10 μm, fusiform to subfusiform or subfusoid-mucronate to ventricoselanceolate with a short attenuate apex, thin-walled, brownish to yellowish brown in KOH and brown to dark brown in

Melzer’s reagent. Caulocystidia forming the meshy ornamentation over surface of stipe, similar to pleurocystidia and cheilocystidia morphologically, some with one septum. Hymenophoral trama bilateral, composed of broad hyaline hyphae 5–11.5 μm in width. Pileus covering (squamules on pileus) composed of more or less vertically to almost radially arranged to loosely interweaved, yellowish brown to brownish or brown, filamentous hyphae 5–10.5 μm in diameter; terminal cells 15–46×6–11 μm, subcylindric. Pileal trama made up of hyphae 3–10.5 μm in diameter, hyaline to yellowish brown in KOH. Clamp connections absent in all tissues. Habitat: Solitary on the ground in the forest of Fagaceae plants.

Index Fungorum Number: IF809891