Panaeolus parvisporus Voto & Angelini

Panaeolus parvisporus (Ew. Gerhardt) Voto & Angelini, Mycological Observations 9: 21 (2024) Fig. 16 Description. Pileus 16–38 mm in diam., ovoid when young, then parabolic or occasionally convex when getting mature, light brown (pantone 4685 c), brown (pantone 4645 c), surface dry, surface could be cracked with erect darker scales, margin slightly exceeding gills. Lamellae adnate, close, broad, mottled grayish first then becoming blackish-brown when mature, entire, with a white edge. Stipe equal, hollow, 19–54 mm long, 2–4 mm thick, brown, usually con-color with the pileus, smooth, pruinose, base with whitish mycelium, base getting darker when touched or bruised. Basidiospores 14.4–16.9 × 9.6–11.1 μm, [x = 15.7 ± 0.6 × 10.4 ± 0.5, Q = 1.4–1.6, Q m = 1.5 ± 0.1, n = 20], ellipsoid, elongate, blackish brown when mature, smooth, thick wall, germ pore distinctive. Basidia 26.4–33.8 × 9.6–12.1 μm, 4 - spored, smooth, hyaline. Cheilocystidia 18.6–30.4 × 3.5–8.2 μm, cylindrical or narrowly clavate, flexuose, occasionally with an inflated apex, hyaline and yellowish-brown, smooth. Pleurocystidia absent. Cuticle composed of large vesicles, pileocystidia 23.3–46.5 × 11.5–28.1 μm, spheropedunculate, hyaline, occasionally yellowish-brown. Caulocystidia 17.7–60.2 × 3.4–7.4 μm, cylindrical or narrowly clavate, flexuose, hyaline, occasionally light brown, smooth. Habitat. Grows on fertile soil as pastures, grasslands, and forests. Psilocybin-producing. Nonproducing (ZRL 20170604, see Suppl. material 1: fig. S 3). Notes. Panaeolus parvisporus is a recently proposed species based on P. papilionaceus var. parvisporus from the P. papilionaceus complex (Voto and Angelini 2024). Five samples from China share identical ITS sequences with two European samples of P. parvisporus. However, they differ in basidiospores, with our samples having larger basidiospores. Specimens examined. China. Inner Mongolia Autonomous Region: Hulunbeier, Xinbaerhuzuo County, 49°45'20"N, 120°12'9"E, alt. 510 m, 26 August 2017, Zhilin Ling, ZRL 20170602, ZRL 20170603, ZRL 20170604, ZRL 20170654; Inner Mongolia Autonomous Region, Chaihe Wildlife Nature Reserve, Zhalantun City, 25 August 2017, Zhilin Ling, ZRL 20170634; Ningxia Hui Autonomous Region: 11 September 1995, Xiaolan Mao, Cangkuan Wang, HMAS 69762.