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.