Parasola haizhuensis Kun L. Yang, Jia Y. Lin & Zhu L. Yang, 2025

Yang, Kun L., Lin, Jia Y., Li, Guang-Mei & Yang, Zhu L., 2025, Introducing one new genus and two new species of Psathyrellaceae (Basidiomycota, Agaricales), with notes on Candolleomyces and Ephemerocybe, Phytotaxa 702 (1), pp. 1-28 : 13

(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 ).

Figures

FIGURE 6. Parasola haizhuensis (photos by Jia Y. Lin, drawings by Kun L.Yang from HKAS145963 (holotype)).a–c. Basidiomata (a–b. HKAS145963 (holotype); c. HTBM2191). d. Cheilocystidia. e. Basidiospores. f. Hymenium, subhymenium, and lamella trama, including a pleurocystidium. g. Sclerocystidia in pileipellis. Bars: b = 1 cm, c = 5 mm, d = 20 µm, e–g = 10 µm.