Lepiota huangyangshanensis M. L. Han, L. A. Wang & Q. An 2026, sp. nov.

Lepiota huangyangshanensis M. L. Han, L. A. Wang & Q. An sp. nov. Figs 2 a, 3 Etymology. The specific epithet huangyangshanensis (Latin) refers to the location of the species in Huangyangshan National Forest Park. Holotype. China • Hebei Province, Zhangjiakou, Zhuolu County, Huangyangshan National Forest Park, 39°52'59.24"N, 115°07'24.39"E, 1,300 m asl., 6 September 2023, on ground, leg. L. A. Wang, ZL-2-18 (LFNC 0002564). Diagnosis. Similar to L. omninoflava Y. J. Hou & Z. W. Ge, but distinguished by its pileus covering and stipe covering composed of chains of either spherical or cylindrical cells, narrowly clavate to clavate cheilocystidia, and smaller thick-walled basidiospores (3.1–4.8 × 2.0–3.1 µm). Description. Basidiomata small, gregarious. Pileus 11–18 mm in diameter, initially campanulate to parabolic, becoming convex to applanate-convex on maturity; surface dull and dry; background cream (4 A 2 / 3) to straw-yellow (3 A / B 3), with denser straw-yellow (3 A / B 3) squamules at center becoming sparse olivaceous buff (4 C 4) towards margin; context white (1 A 1); margin decurved becoming straight at maturity. Lamellae free, white (1 A 1), moderately crowded, up to 1.8–2.0 mm wide, with 2–3 series of lamellulae; margin fimbriate, concolorous with faces. Stipe 23–44 × 1.5–3 mm, central, subcylindrical, hollow, with rhizomorphs; surface cream (4 A 2 / 3) to buff (4 A 4), with irregular cream (4 A 2 / 3) to olivaceous buff (4 C 4) squamules towards the base. Volva absent. Odor not distinctive. Basidiospores [100 / 2 / 2] (2.8 –) 3.1–4.8 (– 5.8) × (1.5 –) 2–3.1 (– 4.1) µm, X mm = 4.02 ± 0.50 × 2.35 ± 0.42, Q = 1.46–2.25, Qm = 1.72 ± 0.15, ellipsoid in frontal view, ellipsoid or oblong in side view, hyaline, thick-walled (0.2–0.4 µm), smooth, with guttules, dextrinoid, congophilous, cyanophilic, not metachromatic, without suprahilar depression and germpore. Basidia 14–20 × 4.5–7.5 µm, clavate to broadly clavate, with guttulate contents, hyaline, thin-walled, 4 - spored; sterigmata up to 4 µm long. Lamellar trama subregular; hyphae 3.5–6.8 µm wide, hyaline, thin-walled. Cheilocystidia 14.5–24 × 5.0–9.5 µm, narrowly clavate to clavate, hyaline, thin-walled. Pleurocystidia absent. Pileus trama interwoven, composed of slightly inflated, septate, 3.8–6.5 µm wide, thick-walled to solid, hyaline hyphae. Pileus covering composed of two types of agglutinated chains of terminal cells forming squamules. One type of chains formed by spherical cells, 19–41 × 9.5–35 μm, ellipsoid, subglobose to globose, often collapsed, easily detachable, thick-walled, basal cells cylindrical or narrowly clavate to clavate; the other type of chains consists of cylindrical to elongated cells, 22–52.4 × 6.7–18 μm, terminal cells with rounded or tapered apex, thick-walled. Both type of chains with pale yellowish to yellowish brown intracellular pigments. Stipe covering a cutis made up of hyphae 3.1–4.9 μm, hyaline in KOH, thin-walled to slightly thick-walled, with or without clamps, terminal elements made up of two types of agglutinated chains forming squamules. One type of terminal cells of chains formed by spherical cells, 21–55 × 9–13 μm, ellipsoid, subglobose to globose, often collapsed, easily detachable, thick-walled, basal cells cylindrical or narrowly clavate to clavate. The other type of chains consists of elongated cells, 14–38 × 11–27 μm, terminal cells with rounded or tapered apex, thick-walled. Both type of chains containing pale yellowish to brown intracellular pigments. Clamp connections present in all parts of basidiomata. Habitat and distribution. Solitary on the ground in mixed coniferous and broad-leaved forests dominated by Pinus tabuliformis, Quercus spp., Betula platyphylla, and Populus davidiana, Hebei province, China. Additional specimens examined (paratype). China • Hebei Province, Zhangjiakou, Zhuolu County, Huangyangshan National Forest Park, 39°52'58.6"N, 115°07'25.8"E, 1,300 m asl., 6 September 2023, on ground, leg. M. L. Han, Han 27 (LFNC 0002565). Notes. Lepiota huangyangshanensis and L. pseudoasperula (Knudsen) Knudsen formed a well-supported lineage (BS = 100 %, BPP = 1.00, Fig. 1) within sect. Eriophorae. Morphologically, L. pseudoasperula resembles L. huangyangshanensis in possessing white lamellae and basidiospores of a similar size (4.0–5.0 × 2.2–3.0 µm). However, L. pseudoasperula can be distinguished by its light to pale cream pileus with dark brown scales, a white stipe bearing residual woolly tomentum with brown scales, and the absence of cheilocystidia (Malysheva 2005). Lepiota omninoflava has similarly colored basidiomata to L. huangyangshanensis; however, it is distinguished by its pileus covering composed of chains of subglobose or ellipsoidal cells, the absence of cheilocystidia, and longer (5.0–6.0 µm), thin-walled basidiospores (Hou and Ge 2020). Lepiota keralensis Pious & T. K. A. Kumar, a recently described species in sect. Eriophorae from southern India, differs from L. huangyangshanensis in its white pileus surface with brownish squamules, as well as its larger basidiospores (5–7 × 3–5 µm; Pious and Kumar 2025).