Hemileccinum pruinatus N.K. Zeng, R.X. Zhao & H. Zeng, 2025

Hemileccinum pruinatus N.K. Zeng, R.X. Zhao & H. Zeng , sp. nov. ( FIGS. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

MycoBank: MB 855892

Etymology: Latin “ pruinatus ” refers to the surface of the pileus covered with a thin pruina.

Diagnosis: Differs from other Hemileccinum species by a reddish brown pileus covered with a thin layer of white pruina, a pale brown, brown to reddish brown stipe, and an inner layer of pileipellis composed of slightly inflated hyphae (up to 10 µm wide).

Holotype: CHINA. Fujian Province: Wuyi County, Wuyi Mountain National Forest Park, elev. 1100 m, 16 August 2023, N. K. Zeng7970 ( FHMU7720 ). GenBank accession numbers: 28 S = PQ346060 , ITS = PQ346070, TEF 1 = PQ355451.

Description: Basidiomata small-sized. Pileus 2–5 cm in diameter, subhemispherical, then convex; surface dry, nearly smooth, pale brown (5A3), brown (6B5) to reddish-brown (6B8), covered with a thin layer of white pruina; context 0.15–0.5 cm thick in the center of the pileus, white, sometimes tinged with pinkish or brownish, unchanging in color when injured. Hymenophore poroid, depressed around apex of stipe; pores angular to subround, yellow (1A2), unchanging in color when injured; tubes 0.25–0.8 cm in length, yellowish (4A2), unchanging in color when injured. Stipe 4.5–10.6 × 0.4–0.8 cm, central, subcylindrical; surface dry, densely covered with pale brown (5A2), brown (5B4) to reddish-brown (6A6) scales; context white, sometimes tinged with pinkish or brownish, unchanging in color when injured; basal mycelium white. Odor indistinct.

Basidia 14–26 × 5–10 μm, clavate, thin-walled, colorless in KOH; four-spored, sterigmata 2–4 μm in length. Basidiospores [180/9/7] (8–) 9–11 (–12) × 4–5 μm, Q= 1.80–2.50, Qm = 2.14 ± 0.19, slightly thick-walled (up to 0.7 μm), subfusiform and inequilateral in side view with distinct suprahilar depression, subfusoid in ventral view, yellowish to brownish in KOH, smooth under light microscopy, but with bacillate ornamentation or tiny warts under SEM. Hymenophoral trama composed of colorless in KOH, 5–10 μm wide, thin to slightly thick-walled (up to 0.5 μm) hyphae. Cheilocystidia 35–43 × 8–11 μm, fusiform or subfusiform, thin-walled, colorless in KOH, no encrustations. Pleurocystidia 35–49 × 8–11 μm, fusiform or subfusiform, thin-walled, colorless in KOH, no encrustations. Pileipellis a hyphoepithelium 106–115 μm thick, composed of slightly inflated hyphae 4–10 µm wide, slightly thick-walled (up to 1 μm), with narrowly cylindrical to subcylindrical terminal cells 11–30 × 4–5 μm. Pileal trama made up of hyphae 11–18 μm in diameter, slightly thick-walled (up to 1 μm), colorless in KOH. Stipitipellis a trichoderm-like structure 59–101 μm thick, composed of thin-walled, emergent hyphae, colorless to yellowish in KOH, with cylindrical, clavate to subovoid terminal cells (18–56 × 6–13 μm). Stipe trama composed of parallel hyphae 6–12 μm wide, subcylindrical, slightly thick-walled (0.5–1 μm), colorless in KOH. Clamp connections absent in all tissues.

Habitat: Solitary or gregarious on the ground in forests dominated by fagaceous trees.

Known distribution: Southeastern China ( Fujian Province); probably central China ( Hunan Province) ( FIG. 1 View FIGURE 1 ).

Additional specimens examined: CHINA. Fujian Province: Wuyi County, Wuyi Mountain National Forest Park , elev. 1100 m, 17 August 2023, N. K. Zeng 7977 ( FHMU7721 ) ; same location and date, N. K. Zeng 7993 ( FHMU7722 ) ; same location and date, N. K. Zeng 7996 ( FHMU7723 ) ; same location and date, N. K. Zeng 8004 ( FHMU7724 ) ; same location and date, N. K. Zeng 8021 ( FHMU7725 ) ; same location and date, N. K. Zeng 8022 ( FHMU7726 ) .