Conferticium subtropicum S. H. He & S. L. Liu 2025, sp. nov.

Conferticium subtropicum S.H. He & S.L. Liu, sp. nov. MB 843411. Fig. 3. Etymology: The species epithet “ subtropicum ” refers to the distribution in subtropical areas in southern China. Typus: China, Zhejiang Province, Kaihua County, Gutianshan Nature Reserve, on fallen angiosperm trunk, 13 Aug. 2013, S. H. He, He 1827 (holotype BJFC 016294, isotypes in BJM, CFMR). Basidiomes annual, resupinate, effused, closely adnate, inseparable from substrate, coriaceous to crustose, up to 40 cm long, 6 cm wide, 100–200 µm thick. Hymenophore smooth to slightly tuberculate with scattered small tubercles, greyish orange [6B(3–6)], brownish orange [6C(4–8)] to light brown [6D(4–8)], immediately turning black in KOH, uncracked or densely cracked with age; margin thinning out, indistinct, usually indeterminate, concolourous with hymenophore. Hyphal system monomitic; all hyphae without clamps. Subiculum indistinct; subhymenium thickening, with a compact texture; generative hyphae colourless, thin-walled, smooth, interwoven, moderately branched and septate, 2–4 µm diam. Pseudocystidia numerous, originated from the base of subhymenium, stretched to hymenium, hyphoid, colourless to pale yellow, distinctly thick-walled, with a narrow lumen often enlarged at apex, smooth, dextrinoid, cyanophilous, vertically arranged, 5–6 µm diam. Basidia clavate, colourless, thin- to thick-walled, smooth, repetitive, often projecting beyond the hymenium, with one to several constrictions, with four sterigmata and a basal simple septum, 35–55 × 4–6 µm; basidioles dominant, in shape similar to basidia, but slightly smaller. Basidiospores ellipsoid, colourless, thin-walled, smooth, amyloid, acyanophilous, (4–)4.5–5 × 2.5–3 µm, L = 4.7 µm, W = 2.7 µm, Q = 1.7 (n = 40/2). Additional specimens examined: China, Hunan Province, Dong’an County, Shunhuangshan Nature Reserve, on fallen angiosperm branch, 13 Jul. 2015, S. H. He, He 2387 (BJFC 020841, CFMR); Jiangxi Province, Lianping County, Jiulianshan Nature Reserve, on fallen angiosperm trunk, 14 Aug. 2016, S. H. He, He 4373 (BJFC 023814, CFMR); Yunnan Province, Lushui County, Gaoligongshan Nature Reserve, on fallen angiosperm trunk, 28 Nov. 2015, S. H. He, He 3317 (BJFC 021712, CFMR); Binchuan County, Jizhushan Nature Reserve, on stump of Quercus, 30 Aug. 2015, S. H. He, He 2814 (BJFC 026769) & He 2833 (BJFC 026770); Zhejiang Province, Kaihua County, Gutianshan Nature Reserve, on fallen angiosperm trunk, 12 Aug. 2013, S. H. He, He 1804 (BJFC 016271). Notes: Conferticium subtropicum is characterized by yellow to brown basidiomes, numerous pseudocystidia and smooth basidiospores. In the phylogenetic tree (Fig. 1), Cm. subtropicum formed a strongly supported lineage sister to Cm. ochraceum, the type species of the genus. Morphologically, Cm. ochraceum differs from Cm. subtropicum by having typical gloeocystidia, enclosed basidia and a distribution in temperate areas mainly on gymnosperm trees (Wu 1996).