Scleroderma nastii Raut

(1.4) Scleroderma nastii Raut, in Raut, Basukala, Shrestha & Poudel, Studies in Fungi 5(1): 53 (2020) (Fig. 6) Description:— Basidiomata small, 10–17 mm in diameter, 16–25 mm in height including a stipe 6–9 mm long, subglobose to tuberiform; odor unknown; taste unknown. Peridium leathery, 0.5–1 mm thick, merino white (#F9F5EC) to lotus-root orange (#F5E9D9), without a color change or turning reddish after damaged, with thin, flaky to felty, meat brown (#D7B19D) to beaver brown (#9D7B69) squamules. Gleba compact at first, becoming pulverulent, flint brown (#736960). Basal rhizomorphs abundant, whitish to yellowish. Basidiospores {40/3/3} (8) 8.5–10 (11) [9.56 ± 0.68, 10.00] µm in diameter including ornamentation, mostly globose, rarely subglobose, thick-walled, with echinulate to subreticulate ornamentation 0.5–1.5 µm high, brownish to purplish, often surrounded by remnants of placental cells. Basidia collapsed. Gleba trama composed of 2.5–5 μm wide, thin-walled to slightly thick-walled, nearly colorless to slightly brownish, compact, moderately branching, subregularly arranged to interwoven hyphae occasionally with clamp connections. Peridial squamules composed of 3.5–10 μm wide, thin-walled to slightly thick-walled, brownish, moderately compact, moderately to frequently branching, interwoven hyphae without clamp connections. Peridial trama composed of 2.5–6.5 μm wide, thin-walled to slightly thick-walled, nearly colorless to slightly brownish, compact, moderately to frequently branching, subregularly arranged to interwoven hyphae without clamp connections. Habits and distribution:— Gregarious, on soil, usually in subtropical forests, associated with plants of Cupressaceae, Fagaceae, Juglandaceae and Pinaceae (Cho et al. 2022). Currently known from Asia (China, Nepal, Pakistan & South Korea) with molecular evidence. Collections examined:— China, Jiangsu Province, Nanjing City, Xuanwu District, Zijinshan Mountain, 32°03'22"N, 118°51'53"E, elevation 80 m, June 3, 2023, Xia Chen & Kun L. Yang, ChenXia302-S23107 (HTBM0350); same location, June 19, 2023, Xia Chen & Kun L. Yang, ChenXia333-S23169 (HTBM0412). China, Jiangsu Province, Nanjing City, Xuanwu District, Zijinshan Mountain, 32°02'59"N, 118°51'13"E, elevation 59 m, August 11, 2023, Xia Chen & Jia Y. Lin, ChenXia497-S23363 (HTBM1474). Notes:— Our collections from China (HTBM0350, HTBM0412 & HTBM1474) and another two collections from South Korea (KA13-0718) and Pakistan (ANSW1) gathered by other researchers are very closely related to the holotype of S. nastii (KATH-FB11) from Nepal in the ITS sequence, so they are recognized as a single species in this study. The morphological description based on our collections is generally consistent with the protologue (Raut 2020) and a report from South Korea (Cho et al. 2022). This is the first report of S. nastii in China. The above-mentioned collections, although all recognized as S. nastii, do establish a paraphyletic group clinging to the clade represented by four collections of another species, S. vinaceum (KUN-HKAS73723 (holotype), KUN-HKAS126617, 1188_TKK_mateba & mOTU37), in the current phylogeny (Fig. 1). However, the clade of S. vinaceum shows homogeneous internal variation and is issued by a distinct branch representing a genetic difference of 1.16% with significant support, suggesting that the relationship between it and S. nastii is possibly unresolved. According to the phylogenetic position, this species may be poisonous to cause gastroenteritis and psycho-neurological disorder.