Chalciporus hainanensis Ming Zhang & T. H. Li

Zhang, Xu, Li, Xin-Ni, Liang, Wei-Qing, Mu, Xiao-Dong, Yu, Ye-Fei, Wu, Xiao-Jun, Chen, Si-Yu, Pu, Jin-Bao & Zeng, Nian-Kai, 2025, The subfamily Chalciporoideae (Boletaceae, Boletales) in China, MycoKeys 124, pp. 123-157 : 123-157

Chalciporus hainanensis Ming Zhang & T. H. Li , Phytotaxa 327 (1): 47–56, 2017

Figs 2 i , 6

Description.

Basidiomata very small-sized. Pileus 1–2 cm in diameter, subhemispherical to convex when young, plano-convex to applanate when mature; surface dry, tomentose, light orange-brown (5 A 3–5 A 4); context 0.2–0.5 cm in thickness in the center of the pileus, white (1 A 1), changing red when bruised. Hymenophore poroid, slightly decurrent; pores angular, about 0.1 cm wide, reddish orange (6 A 5–6 A 6); tubes about 0.2 cm long, reddish orange (6 A 5). Stipe 1.1–2.3 × 0.2 cm, central, solid, subcylindrical; surface orange-brown to brown (5 B 4–5 B 6), but reddish at the apex, with distinctly longitudinal striations; context white (1 A 1), changing red when bruised; basal mycelium white. Odor indistinct. Taste mild.

Basidiospores [80 / 4 / 1] 7.5–10 × 3.5–5 μm, Q = (1.70) 1.88–2.50 (2.57), Q m = 2.16 ± 0.19, yellowish brown in KOH, elongated to cylindrical, thin-walled, smooth under the light microscope. Basidia 17–30 × 8–10.5 μm, clavate, thin-walled, 4 - spored, colorless in KOH; sterigmata 3–5 μm in length. Cheilocystidia 17–31 × 6–12 μm, fusiform or subfusiform, slightly thick-walled (up to 1 μm), colorless in KOH. Pleurocystidia 22–35 × 7–10 μm, fusiform or subfusiform, slightly thick-walled (up to 1 μm), colorless in KOH. Hymenophoral trama boletoid, yellowish in KOH, thin- to slightly thick-walled (up to 0.5 μm), 3–11 μm wide. Pileipellis a trichoderm 200–350 μm in thickness, composed of pale yellow in KOH, slightly thick-walled (up to 1 μm) hyphae; terminal cells 20–65 × 7–9 μm, clavate to subcylindrical or cystidioid. Pileus trama made up of hyphae 1–9 μm in diameter, thin-walled, colorless to pale yellow in KOH. Stipitipellis a trichoderm-like structure 150–250 μm thick, composed of hyaline to pale yellow in KOH, slightly thin-walled (up to 1 μm) hyphae; terminal cells 10–30 × 5–8 μm, clavate or subcylindrical, occasionally fusiform. Stipe trama composed of parallel hyphae 4–15 μm in diameter, cylindrical, thin-walled, yellow in KOH. Clamp connections absent in all tissues.

Habitat.

Solitary or gregarious on the ground in forests dominated by fagaceous trees ( Castanopsis spp. , Cyclobalanopsis spp. , Lithocarpus spp. ).

Known distribution.

Southern ( Hainan Province) and southeastern China ( Fujian Province).

Holotype.

GDGM 44464 ( China, Hainan Province) (non vidi) .

Materials examined.

China • Fujian Province, Jiangle County, Longqishan National Nature Reserve , elev. 750 m alt. 650 m, 26.4°N, 117.2°E, 21 August 2023, N. K. Zeng 8211 ( FHMU 9951 ) ; • Hainan Province, Baisha County, Yinggeling of Hainan Tropical Rainforest National Park , elev. 550 m, 26 June 2015, S. Jiang 81 ( FHMU 4573 ) .

Notes.

Chalciporus hainanensis was originally described from Hainan Province of southern China ( Zhang et al. 2017). In the present study, it was also found to be distributed in Fujian Province of southeastern China. The species is characterized by a very small basidioma, a tomentose, light orange-brown pileus, a reddish-orange hymenophore surface, and a trichodermal pileipellis.

Figures

Figure 2. Basidiomata of fungi in the subfamily Chalciporoideae a, b. Buchwaldoboletus lignicola (FHMU 5579); c – e. Chalciporus aurantiolepidotus (c, e FHMU 7049, holotype; d FHMU 7472); f – h. C. brunneus (FHMU 8246, holotype); i. C. hainanensis (FHMU 9951); j – l. C. roseus (FHMU 7888, holotype); m – o. Pseudophylloporus castaneus (ZJMR 330727230331, holotype). Scale bars: 1 cm. a – l. photos by N. K. Zeng; m – o. photos by J. B. Pu.

Figure 6. Microscopic features of Chalciporus hainanensis (FHMU 9951). a. Basidia; b. Basidiospores; c. Cheilocystidia; d. Pleurocystidia; e. Pileipellis; f. Stipitipellis. Scale bars: 10 µm. Drawings by X. N. Li.