Introducing one new genus and two new species of Psathyrellaceae (Basidiomycota, Agaricales), with notes on Candolleomyces and Ephemerocybe Author Yang, Kun L. 0000-0001-5365-6693 College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, Guangdong, China mugoture@gmail.com Author Lin, Jia Y. 0009-0000-3488-2169 College of Plant Protection, South China Agricultural University, Guangzhou 510642, Guangdong, China mycofloscula@gmail.com Author Li, Guang-Mei 0009-0005-9487-735X Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China liguangmei@mail.kib.ac.cn Author Yang, Zhu L. 0000-0001-9745-8453 Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China fungi@mail.kib.ac.cn text Phytotaxa 2025 2025-05-22 702 1 1 28 https://doi.org/10.11646/phytotaxa.702.1.1 journal article 311905 10.11646/phytotaxa.702.1.1 86eb24b0-138a-4bcf-815d-95c20b405c2a 1179-3163 16725027 (2.1) Parasola haizhuensis Kun L. Yang, Jia Y. Lin & Zhu L. Yang , sp. nov. ( Fig. 6 ) Registration identifier:— FN572409 Etymology:— Refers to the type locality, Haizhu District in Guangzhou City. Diagnosis:— Similar to Parasola cinnamomescens , Pa. conopilea and Pa. psathyrelloides , but differing from them by an undulate pileus margin. Type:— China , Guangdong Province , Guangzhou City , Haizhu District , Shangchong Fruit Tree Park , 23°04’36”N , 113°18’21”E , elevation 2 m , August 3, 2024 , Jia Y. Lin , L24207 ( HKAS145963 , holotype (ITS: PV155174 ; nrLSU: PV147348 ; tef-1α : PV156693 ; β-tub : PV156731 ); HTBM2192 , isotype ) . Description:— Basidiomata psathyrelloid, tiny to small, fragile, not deliquescent nor collapsing. Pileus 6–14 mm in diameter, paraboloid, sandal brown (#BA8B70) to copper orange (#A56B34), slightly darker at the center; veil absent; margin undulate, slightly sulcately striate nearly up to the center. Lamellae adnexed, crowded, rhinoceros brown (#DBC299), with an entire to serrate, pale edge, interspersed with abundant lamellulae. Stipe 24–42 mm long, 1.5–3 mm thick, cylindrical to subcylindrical, hollow, slightly striate, merino white (#F9F5EC), with fibrous, ceramic white (#FEFEFA) squamules, without an annulus. Odor fungal. Taste fungal. Basidiospores {40/2/2} (10) 10.5–12 (12.5) [11.31 ± 0.60, 11.00] × (5) 5.5–7.5 (8) [6.73 ± 0.70, 6.50] µm, Q = (1.40) 1.44–2.09 (2.30) [1.70 ± 0.19, 1.69], more or less amygdaliform or fusiform, thick-walled or slightly thick-walled, brownish in both water and 5% KOH, smooth, with a small apiculus and a central germ pore. Basidia 33– 36 × 8.5–11.5 μm, clavate, mostly four-spored, rarely two-spored, thin-walled to slightly thick-walled, very slightly brownish, with sterigmata up to 4.5 µm long, surrounding by basidioles 12–21 × 8–11 μm. Hymenial physalides poorly developed. Lamella trama subregular, composed of 2.5–5.5 µm wide, slightly thick-walled, brownish, compact, moderately branching hyphae. Cheilocystidia very abundant, 48–109 × 10–28 µm, more or less utriform, thin-walled to slightly thick-walled, smooth, nearly colorless. Pleurocystidia rare, 60–115 × 14.5–24 µm, clavate, thin-walled to slightly thick-walled, smooth, nearly colorless. Pileipellis generally hymeniform, composed of thin-walled to slightly thick-walled, clavate, slightly brownish terminal cells measured 21–32 × 10–18 µm, mixed with some thick-walled, brownish sclerocystidia 65–200 × 1.5–5 µm. Clamp connections occasionally present in lamella trama, absent elsewhere. Habits and distribution:— Gregarious, on dead branches, in subtropical orchards. Currently known from South China . Other collection examined:— China , Guangdong Province , Guangzhou City , Haizhu District , Shangchong Fruit Tree Park , 23°04’36”N , 113°18’21”E , elevation 2 m , August 3, 2024 , Jia Y. Lin , L24206 ( HTBM2191 ).