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

Lepiota xiaowutaishanensis M. L. Han, L. A. Wang & Q. An sp. nov. Figs 2 i, 6 Etymology. The specific epithet xiaowutaishanensis (Latin) refers to the location of the species in Xiaowutaishan National Nature Reserve. Holotype. China • Hebei Province, Zhangjiakou, Yu County, Xiaowutaishan National Nature Reserve, 39°46'20.36"N, 114°51'48.33"E, 1,350 m asl., 7 September 2023, on ground, leg. L. A. Wang, YX-2-7 (LFNC 0002562). Diagnosis. Similar to Lepiota psalion Huijser & Vellinga, but differs in a white, flesh-pink to clay-pink pileus and a larger stipe (60–88 × 3–6 mm). Description. Basidiomata small, gregarious. Pileus 1.8–2.5 cm in diameter, conical to parabolic when young, becoming convex at maturity; surface dull and dry, white (1 A 1), flesh-pink (8 A 3 / 9 A 4) to clay-pink (6 B / C 4), smooth; context white (1 A 1), soft, thin ca. 3-4 mm; margin decurved becoming straight at maturity. Lamellae free, crowded with 1–3 tiers of lamellulae, white (1 A 1) to clay-pink (6 B / C 4); margin entire and slightly wavy. Stipe 60–88 × 3–6 mm, central, cylindrical, equal at base, fibrillose, hollow; white (1 A 1), flesh-pink (8 A 3 / 9 A 4) to fawn (7 D / E 4). Volva absent. Odor not distinctive. Basidiospores [100 / 3 / 2] (3.0 –) 3.5–5.0 (– 5.1) × (2.0 –) 2.3–3.5 (– 4.0) µm, Xmm = 4.37 ± 0.47 × 2.94 ± 0.33, Q = 1.17–1.96, Qm = 1.50 ± 0.17, thick-walled (0.3–0.6 µm), ellipsoid in frontal view, ellipsoid, broadly ellipsoid to oblong in side view, some slightly truncate, hyaline, smooth, with refractive guttules, dextrinoid, congophilous, cyanophilic, not metachromatic, without suprahilar depression and germpore. Basidia 13–21 × 4–6.5 μm, thin-walled, frequently 4 - spored, rarely 2 - spored, clamped, clavate, hyaline in KOH. Lamellar trama subregular; hyphae 2.1–4.1 µm wide, hyaline, thick-walled. Cheilocystidia 20.1–28.9 × 5.0–10.0 µm, clavate to broadly clavate, smooth, thin-walled, hyaline in KOH. Pileal trama interwoven, composed of slightly inflated, septate, 2.5–4.0 µm wide, thick-walled to solid, hyaline hyphae. Pileus covering a hymeniderm composed of erect, broadly clavate or narrowly clavate elements 13.3–43.5 × 9.8–20.8 um, thick-walled, with or without clamp connections, containing grayish yellow intracellular pigments. Stipe covering a cutis composed of hyphae 3.1–5.1 μm wide, parallel, compactly arranged, thick-walled to solid, occasionally branched, hyaline or yellowish, with or without clamp connections; terminal elements extremely narrowly clavate, with rounded apex, 61.9–183.2 × 5.4–13.2 μm, containing green-yellow 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 and Betula platyphylla, Hebei Province, China. Additional specimens examined (paratype). China • Hebei Province, Zhangjiakou, Yu County, Xiaowutaishan National Nature Reserve, 39°46'25.12"N, 114°51'54.85"E, 1,400 m asl., 7 September 2023, on ground, leg. M. L. Han, Han 5 (LFNC 0002563). Notes. Phylogenetic analysis shows that L. xiaowutaishanensis is closely related to L. thiersii Sundb., L. recondita Tatti, Huijser & Vizzini, and L. sinorecondita, forming a distinct cluster (Fig. 1). Morphologically, all four species share similarly sized basidiospores. However, in contrast to L. xiaowutaishanensis, the other three species exhibit dark pilei and non-dextrinoid basidiospores (Sundberg 1989; Vizzini et al. 2019). Lepiota psalion has basidiospores similar in size and shape, a hymeniform pileus covering, and clavate cheilocystidia similar to those of L. xiaowutaishanensis. However, it can be distinguished by its cream to pinkish-light brown pileus with concentric, non-uplifted squamules and a smaller stipe (22–33 × 1.5–2 mm; Vizzini et al. 2019).