Scleroderma xanthochroum Watling & K. P. Sims

(2.5) Scleroderma xanthochroum Watling & K.P. Sims, Memoirs of the New York Botanical Garden 89: 95 (2004) (Fig. 14) Description:— Basidiomata small to medium-sized, 21–81 mm in diameter, 12–49 mm in height including a stipe 3–18 mm long, subglobose to tuberiform; odor fungal; taste unknown. Peridium leathery, 1–4 mm thick, brick orange (#ECE2B4), desert orange (#E8D7B0) to mongoose brown (#B5A284), with a milky yellow (#FFF07A) to sun orange (#FCD742) context, becoming darker after damaged, nearly smooth. Gleba compact at first, becoming pulverulent, coal blue (#40474D) to dull black (#0B0C0E). Basal rhizomorphs abundant, yellowish. Basidiospores {40/1/1} 7–8.5 (9.5) [7.96 ± 0.53, 8.00] µm in diameter including ornamentation, mostly globose, rarely subglobose, thick-walled, with echinulate ornamentation 0.5–1 µm high, brownish to purplish, often surrounded by remnants of placental cells. Basidia collapsed. Gleba trama composed of 2–4.5 μm wide, thin-walled to slightly thick-walled, nearly colorless to slightly brownish, compact, moderately branching, subregularly arranged to interwoven hyphae with clamp connections. Peridial surface composed of 3–7 μm wide, thin-walled to slightly thick-walled, yellowish to brownish, moderately compact, moderately branching, interwoven hyphae with clamp connections. Peridial trama composed of 3–10 μm wide, slightly thick-walled, nearly colorless to slightly yellowish, compact, moderately to frequently branching, subregularly arranged to interwoven hyphae with clamp connections. Habits and distribution:— Gregarious, on soil, usually in tropical to subtropical forests, associated with plants of Fabaceae and Gnetaceae. Currently known from Asia (China, Malaysia & Thailand) and Africa (Cameroon) with molecular evidence. Collection examined:— China, Guangdong Province, Shenzhen City, Longgang District, Luzui Villa, exact location unknown, June 29, 2023, Wen-Ting Chen, Kun L. Yang et al., S23236 (HTBM0479). Notes:— Scleroderma xanthochroum was originally described from Peninsular Malaysia, and is new to China. This is one of the numerous cryptic species recognized in the S. sinnamariense complex, see notes for Scleroderma gaibeioides for details.