Boletellus putuoensis N.K. Zeng, Yi Li, Chang Xu, Xu Zhang & J.R. Wang, 2022

Xu, Chang, Zhang, Xu, Chen, Yun-Xia, Xue, Rou, Le, Zhi-Fang, Wang, Jian-Rui, Li, Yi & Zeng, Nian-Kai, 2022, Boletellus putuoensis (Boletaceae, Boletales), a new bolete from subtropical China, Phytotaxa 554 (2), pp. 149-162 : 156-158

Boletellus putuoensis N.K. Zeng, Yi Li, Chang Xu, Xu Zhang & J.R. Wang sp. nov. ( Figs. 2–5 )

Fungal Names no.: FN571000

Etymology:—Latin “ putuoensis ”, refers to the holotype locality of Putuo District, Zhoushan City, Zhejiang Province.

Diagnosis:—Differs from other species of Boletellus s. str. by 28S, ITS, TEF1 and RPB2 sequence data and the following morphological features: very small to small fruitbodies, a brownish black, brown to dark brown, tomentose pileus, a stipe densely covered with brownish black scales, and smaller basidiospores without obvious transverse striations on the ridges when observed under a light microscope.

Holotype:— CHINA. Zhejiang Province: Zhoushan City, Putuo District, Zhujiajian Island , N29°56ʹ05.14′′, E122°24ʹ13.99′′, elev. 33 m, 14 June 2021, Yi Li 3039 ( FHMU6907 , holotype). GenBank accession numbers: atp6 = ON 155836 , 28 S = ON 166664 , ITS = ON 166669 , TEF1 = ON 155822 , RPB 2 = ON 155834 .

Description:— Basidiomata very small to small. Pileus 1.5–4 cm diam, subhemispherical when young, then convex to applanate; margin decurved when young, then uplifted; surface dry, tomentose, brownish black (4E2) when young, brown (6E6) to dark brown (6E4) with age; context 0.65–0.75 cm thick in the center of the pileus, white (1A1), turning blue quickly when injured. Hymenophore poroid, adnate to slightly depressed around the apex of stipe; pores about 0.5 mm diam, angular, yellow(1A4), turning blue quickly when injured; tubes 0.6–1 cm in length, yellowish (1A2), turning blue quickly when injured. Stipe 2.9–4.5 × 0.6–1.4 cm, central, subcylindrical, solid; surface dry, brownish yellow when young, densely covered with brownish black (4E2) scales, sometimes beaded with brown latex when young at the base of stipe; context yellowish white (2A1), turning blue quickly when injured; annulus absent; basal mycelium whitish. Odor indistinct.

Basidiospores [160/8/4] (9–)9.5–12 × 5–6 μm, Q = 1.67–2.20 (–2.40), Qm = 1.95 ± 0.17, basidiospores (excluding ornamentation) [160/8/4] 8.5–11(–11.5) × 4–5 (–5.5) μm, Q = (1.64–)1.80–2.44 (–2.63), Qm = 2.11 ± 0.22, yellowish brown in KOH, fusiform, with longitudinal or oblique ridges, continuous or rarely interrupted, 5–7 ridges visible in lateral view, united at the apex when young, then cleft, no obvious transverse striations on the ridges observed under light microscope. Basidia 35–40 × 11–14 μm, clavate, thin- to slightly thick-walled (up to 1 μm), 4-spored, hyaline to pale yellow in KOH; sterigmata 3.5–4 μm in length. Cheilocystidia 35–47 × 12.5–16 μm, abundant, fusiform or subfusiform, thin- to slightly thick-walled (up to 1 μm), hyaline in KOH. Pleurocystidia 55–72 × 14–17 μm, subfusiform or fusiform, thin- to slightly thick-walled (up to 1 μm), hyaline to pale yellow in KOH. Pileipellis a trichoderm 200–250 μm thick, composed of hyphae 6–12 µm diam, thin-walled, yellowish brown in KOH; terminal cells 20–23 × 7.5–10 μm, subcylindrical or subclavate, with obtuse apex. Pileal trama made up of hyphae 5–8 μm in diam, slightly thick-walled (up to 1 μm), hyaline to pale yellow in KOH. Stipitipellis a hymeniform layer 600–700 μm thick, composed of slightly thick-walled (up to 1 μm) hyphae, hyaline to pale yellow in KOH, with clavate, subclavate, subfusiform or subcylindrical terminal cells (25–45 × 7–15 μm), and sometimes with clavate, 4-spored basidia. Stipe trama composed of 5–12 μm diam, subcylindrical, thin- to slightly thick-walled (up to 1 μm), yellow in KOH, parallel hyphae. Clamp connections absent in all tissues.

Habitat:—Solitary to gregarious on the ground in mixed forests of Castanopsis ssp. and Pinus massoniana Lamb.

Known distribution:—Eastern China (Zhejiang and Jiangxi Provinces) and southern China (Guangdong Province).

Additional specimens examined:— CHINA. Zhejiang Province: Zhoushan City, Putuo District , Xuanshan Island , N29°42ʹ43.35′′, E122°12ʹ23.61′′, elev. 41 m, 14 October 2021, Yi Li 4536-3 ( FHMU6959 ), Yi Li 4536-4 ( FHMU6960 ); Haiyan County, Baiyunge , N30°22ʹ03.83′′, E120°50ʹ46.59′′, elev. 178 m, 20 August 2021, J. R. Wang s. n. ( FHMU6961 ) . Guangdong Province: Shaoguan City, Renhua County, Danxiashan National Nature Reserve , N25°01ʹ44.72′′, E113°45ʹ58.19′′, elev. 350 m, 4 June 2019, N. K. Zeng 4075 ( FHMU3261 ) .

Figures

FIGURE 2. Basidiomata of Boletellus putuoensis (a, d from FHMU6907, holotype; b–c from FHMU6960). Photos by Y. Li.

FIGURE 3. Microscopic features of Boletellus putuoensis (FHMU6907, holotype). a. Basidia. b. Basidiospores. c. Cheilocystidia. d. Pleurocystidia. e. Pileipellis. f. Stipitipellis. Bars=10 μm. Drawings by X. Zhang.

FIGURE 4. Light micrographs of basidiospores from a dried specimen of Boletellus putuoensis (FHMU6907, holotype). Bars = 20 μm. Photos by J. Ma.

FIGURE 5. SEM of basidiospores from dried specimens of Boletellus putuoensis (a–c fromFHMU6907, holotype; d from FHMU3261). Bars = 2 μm. Photos by Y. Li.