Butyriboletus sinoregius L. Fan & H.Y. Fu, 2022

Fu, Hao-Yu, Li, Ting & Fan, Li, 2022, Two new species of Butyriboletus from China, Phytotaxa 544 (2), pp. 207-219 : 215

Butyriboletus sinoregius L. Fan & H.Y. Fu , sp. nov. 2 ( Fig. 4 )

Mycobank:—MB842145

Diagnosis:—differs from the European B. regiu s by the different phylogenetic position, the basidiomes bluing when bruised and the finely tomentose pileus.

Etymology:—‘ sinoregius ’; sino, means China, ‘ regius ’ refers to this new Chinese species being similar to B. regius .

Holotype:— CHINA. Shanxi Province, Jincheng City, Qinshui County, Zhongcun Forest Farm, on the ground in Fagaceae forest, 35°29′8″N, 112°11′28″E, elev. 1630 m, 22 August 2019, collected by Hong Liu LH 755 ( BJTC FM755 ) .

Description:— Pileus 6.3–7 cm diam., convex to applanate; surface dry, sometimes cracking at centre, finely tomentose, pale purple-red (#ff6b6b), and fading to pale red-orange or grayish orange (#f8f1e2) to margin, margin straight to decurved; context firm and dense, thick, pale yellow (#ffff4d), becoming blue when exposed. Hymenophore (tube layer) surface bright yellow (#ffff1a) to pale yellow (#ffff9a) at first, turning to brownish yellow (#ebc300) when matured, becoming blue when bruised; pores circular to somewhat elongate, 0.3–0.7 mm diam; tubes 4–6 mm deep. Stipe 5.2–6.7 × 1.8–2.3 cm, mostly equal, sometimes slightly widening towards the base, dry, not hollow, pale yellow (#ffff4d), becoming blue when bruised, reticulate; annulus absent; basal mycelium whitish (#ffffff) to soft yellow (#fff281). Odor not distinct. Taste unpleasant, sour and astringent.

Basidiospores [60/3/3] 10–15 × 5–5.5μm [Q = 2–2.68, Q m = 2.34 ± 0.34], subfusiform to fusoid-ventricose, subhyaline in KOH. Basidia 27.5–32.5 × 10–12.5μm, clavate, thin-walled, hyaline in KOH, 3–4-spored; sterigmata short. Hymenophoral trama boletoid. Pleurocystidia 25–42.5 × (5–) 7.5–12.5 (–17.5) μm, smooth, thin-walled, hyaline in KOH, barrel-shaped, or utriform to lageniform with subacute apex; cheilocystidia absent. Pileipellis an interwoven trichoderm, 27.5–50 μm thick, composed of interwoven hyphae, 3–5 μm in diam, hyphae yellow greenish brown (#e1f9b1), hyaline in KOH, smooth, thin-walled, terminal cells nearly clavate sometimes with expanding obtuse. Stipitipellis an interwoven trichoderm-like structure, 145–240 μm thick, composed of thin- to slightly thick-walled (up to 1 μm) hyphae with narrowly or broadly clavate, subfusiform or fusiform terminal cells (14–28 × 3.5–6 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 dominated by Quercus sp. , so far only known from Shanxi Province, China.

Additional specimens examined: CHINA. Shanxi Province, Jincheng City, Lishan Mountains, 16 July 2020, collected by Hong Liu LH 929 (BJTC FM1240); ibid. Linfen City, Yicheng Country, Shihe Forest Farm, Songshu Groove, 35°29′35″N, 112°5′41″E, elev. 1960 m, 26 August 2020, collected by Hong Liu LH1178 (BJTC FM1103).

Figures

FIGURE 4. Morphological features of Butyriboletus sinoregius, a. Basidiome (holotype BJTC FM755), b. Basidiomes (BJTC FM1103) c. Pleurocystidia d. Basidiospores e. Pileipellis f. Stipitipellis. g. Basidia and two pleurocystidia. Scale bars: a, b = 1 cm, c, d, f = 5 μm, e = 30 μm, g = 10 μm. Drawings by Haoyu Fu.