Two new species of Butyriboletus from China Author Fu, Hao-Yu 0000-0001-5529-4964 865001572 @ qq. com; https: // orcid. org / 0000 - 0001 - 5529 - 4964 865001572@qq.com Author Li, Ting 0000-0001-7809-3217 1377090363 @ qq. com; https: // orcid. org / 0000 - 0001 - 7809 - 3217 1377090363@qq.com Author Fan, Li 0000-0001-9887-7086 fanli @ mail. cnu. edu. cn; https: // orcid. org / 0000 - 0001 - 9887 - 7086 fanli@mail.cnu.edu.cn text Phytotaxa 2022 2022-04-29 544 2 207 219 journal article 55787 10.11646/phytotaxa.544.2.7 9c4d80ca-9692-4217-9f6a-de3ab6172c4d 1179-3163 6503921 Butyriboletus brunneoides L. Fan & H.Y. Fu , sp. nov. 1 ( Fig. 3 ) Mycobank :—MB842144 Diagnosis :—differs from Bu. brunneus in the small to medium basidiome with a smooth pileus, a thin stipe that develops reddish stains at the base and the isolated phylogenetic position. Etymology :—‘ brunneoides ’, refers to the similarity to Bu. brunneus . Holotype :— CHINA . Shanxi Province , Jincheng City , Qinshui County , Shangwoquan village , 35°35ʹ1ʺN , 112°4ʹ37ʺE , elev. 1150 m , on the ground under Quercus spp ., 26 July 2021 , collected by Jingchong Lv LJC045 ( BJTC FM1816 ). Description :— Pileus 3.5–9.4 cm in diam., hemispherical to convex, becoming broadly convex when mature; surface dry, smooth, yellowish brown (#ffbb78) to brown ( # c96400), margin decurved; context firm and dense, thick, pale yellow (#ffff68) to yellow (#fffc9a), unchanging when exposed, or turning very slightly pale blue over the tubes. Hymenophore (tube layer) bright yellow (#ffff1a) to light yellow ( # eaff80), changing blue when exposed; pores circular to somewhat elliptical, 0.2–0.3 mm in diam; tubes 2–5 mm deep. Stipe 4.5–6 × 0.7–3 cm , cylindrical, equal, widening towards the base, dry, solid, covered with a fine yellow reticulum; pale yellow ( # eaff80), developing pale red stains near the base changing blue when bruised; annulus absent. Basal mycelium whitish (#ffffff) to pale yellow (#fff281). Odor distinct like salted fish when dry. Taste unpleasant, typically bitter or somewhat tart. FIGURE 3. Morphological features of Butyriboletus brunneoides . a. Basidiomes (BJTC FM1816, holotype), b. Stipitipellis. c. Pileipellis d. Basidiospores e. Cheilocystidia f. Basidia and a pleurocystidium g. Pleurocystidia. Scale bars: a = 2 cm, b, c = 20 μm, d, e, f = 5 μm, g = 10 μm. Drawings by Haoyu Fu. Basidiospores [40/2/2] 11–15(–17) × 3–5 [Q = 3.25–3.75 (4.33), Q m = 3.5 ± 0.25], subfusiform, subhyaline in KOH. Basidia 27.5(–15)–35 × 7.5–10 μm, clavate, thin-walled, 4-spored; sterigmata short. Hymenophoral trama boletoid. Pleurocystidia 35–45 × 8–12.5 μm, smooth, thin-walled, hyaline in KOH, fusoid-ventricose to broadly clavate with subacute apex; cheilocystidia 30–32.5 × 7.5–10 μm, smooth, thin-walled, hyaline in KOH, narrowly clavate to clavate-ventricose. Pileipellis an interwoven trichoderm 37.5–50 μm thick, composed of interwoven hyphae 2.5–5 μm in diam., hyphae yellowish brown (#edb849), hyaline in KOH, smooth, thin-walled, terminal cells cylindric with subglobose or rounded apices. Stipitipellis an interwoven trichoderm-like structure 105–200 μm thick, composed of thin- to slightly thick-walled (up to 1 μm) hyphae with narrowly or broadly clavate, subfusiform or fusiform terminal cells (16–26 × 4–9 μm), and some emergent hyphae with clavate or subcylindrical terminal cells. Stipe trama composed of cylindrical, thin to slightly thick-walled (up to 1 μm), parallel hyphae 3–14 μm diam. Clamp connections absent. Habit, habitat and distribution: solitary or scattered, on ground in a Fagaceae forest, currently only known from Shanxi Province , North China .