Scleroderma pernicococcum Kun L. Yang, Jia Y. Lin & Zhu L. Yang 2025, sp. nov.

(1.5) Scleroderma pernicococcum Kun L. Yang, Jia Y. Lin & Zhu L. Yang, sp. nov. (Fig. 7) Registration identifier:— FN572384 Etymology:— Referring to the possible toxicity of this little earthball fungus. Diagnosis:— Differing from other species in sect. Scleroderma known in Asia by the tiny basidiomata producing a palely colored peridium. Type:— China, Guangdong Province, Guangzhou City, Nansha District, Huangshanlu Forest Park, a green belt along Dengshan Rd., 22°46'22"N, 113°34'21"E, elevation 90 m, August 13, 2023, Jia Y. Lin & Kun L. Yang, K23347 (HKAS145950, holotype (deposited in the Herbarium of Cryptogams in Kunming Institute of Botany of Chinese Academy of Sciences; ITS: PV059084; nrLSU: PV054217); HTBM1219, isotype). Description:— Basidiomata tiny, 3–6 mm in diameter, 3–6 mm in height, subglobose, mostly sessile, rarely shortly stipitate; odor fungal; taste unknown. Peridium leathery, 0.2–0.5 mm thick, ceramic white (#FEFEFA) to merino white (#F9F5EC), turning reddish to purplish after damaged, with thin, flaky to fibrous, concolorous to donkey brown (#AC9B87) squamules to nearly smooth. Gleba compact at first, becoming pulverulent, coal blue (#40474D) to dull black (#0B0C0E). Basal rhizomorphs moderately abundant, whitish. Basidiospores {40/2/1} 9.5–13.5 (14) [11.49 ± 1.24, 11.00] µm in diameter including ornamentation, mostly globose, rarely subglobose, thick-walled, with echinulate ornamentation 0.5–1.5 µm high, brownish to purplish. Basidia 20–32 × 8–10 μm, clavate, four- to eight-spored, thin- to slightly thick-walled, nearly colorless. Gleba trama composed of 2.5–5.5 μm wide, thin-walled to slightly thick-walled, nearly colorless to slightly brownish, compact, moderately branching, subregularly arranged to interwoven hyphae without clamp connections. Peridial surface composed of 2.5– 6 μm wide, slightly thick-walled, brownish, moderately compact, moderately to frequently branching, subregularly arranged to interwoven hyphae without clamp connections. Peridial trama composed of 2–6.5 μm wide, slightly thick-walled, nearly colorless to slightly brownish, compact, moderately to frequently branching, subregularly arranged to interwoven hyphae without clamp connections. Habits and distribution:— Solitary to gregarious, on soil, in subtropical forests, associated with plants of Lauraceae, Myrtaceae, Rubiaceae and Sapindaceae. Currently known from Asia (China, India & Pakistan) with molecular evidence. Other collections examined:— China, Guangdong Province, Guangzhou City, Tianhe District, South China National Botanical Garden, 23°10'52"N, 113°21'17"E, elevation 50 m, June 14, 2023, Kun L. Yang, K23297 (HTBM0812). China, Guangdong Province, Foshan City, Nanhai District, Leigang Park, 23°02'35"N, 113°08'27"E, elevation 59 m, June 22, 2023, Jia Y. Lin & Kun L. Yang, L2394 (HTBM0927). Notes:— According to the phylogenetic position, this species may be poisonous to cause gastroenteritis and psycho-neurological disorder.