Micropsalliota wuyishanensis J. Q. Yan sp. nov. MycoBank: 842898
Etymology: Referring to its type locality (Wuyishan National Park).
Diagnosis: Differs from M. cardinalis by its stipe covered with red fibrils and by its hyphoid, often forked, cheilocystidia. (Figures 2M, 9, 10G)
Basidiomata slender to stout (IG = 28–43). Pileus 6.0– 10 mm in diameter, red (10A6–10B7), campanulate, surface dry, covered with deep red (10C7–10C8) fibrils, margin appendiculate, with white or pinkish remains of the veil. Context less than 0.5 mm thick. Lamellae 0.5–1.0 mm broad, free, moderately distant, with 3 series of lamellulae, white (1A1) becoming light brown (7D5–7D6) as mature. Stipe 18– 25 × 1.0–1.5 mm, cylindrical, uniform, white (1A1), surface with pastel red to dull red (10A4–10B4) fibrils. Annulus single, membranous, white (1A1), superior, fall off when young.
Basidiospores (5.0) 5.5–6.0 (6.5) × 3.0–3.5 (4.0) µm, av. = 5.8 × 3.4µm, Q = 1.60–1.80 (1.90), elongated in face view, amygdaliform in profile view, light brown, without germ pore, inamyloid, thick-walled, with a thickened apical endosporium. Basidia (13) 14–18.5 (20) × (5.0) 6.0–7.0 (7.5) µm, clavate, hyaline, 4-spored. Pleurocystidia absent. Cheilocystidia 33–60 (72) × 3.5–6.0 (6.5) µm, hyaline, hyphoid, tortuous or submoniliform, often branched or forked, apex obtuse or subcapitate, rare capitate. Pileipellis a cutis, hyphae (4.5) 6.5–10 (11) µm in diameter, with pink membranous pigment.
Habit and habitat: Scattered on soil in broad-leaved forests.
Specimens examined: CHINA. Fujian Province, Wuyishan National Park, Jun-Qing Yan, Ya-Ping Hu and Hui Ding, 10 Aug 2021, HFJAU3048, holotype.
Notes: Among known species of Micropsalliota, only M. cardinalis and M. roseipes resemble M. wuyishanensis in having a red pileus 5.0–10 mm in diameter. These two species can be distinguished from the latter as follows: M. cardinalis has capitate cheilocystidia that are less than 35µm long (Heinemann, 1989), and M. roseipes has longer basidiospores (6.2–7.4µm) (Heinemann, 1980). In the phylogenetic tree, M. wuyishanensis formed a distinct lineage, but the phylogenetic position and relationships with other species are still unclear.
