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

Xu, Y. L., Cao, Y. F., Liu, S. L., Nakasone, K. K. & He, S. H., 2025, Taxonomy and phylogeny of Stereaceae (Russulales, Basidiomycota): two new genera, nine new species and twenty new combinations, Persoonia 54 (1), pp. 119-145 : 130

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).

Figures

Fig. 3. Conferticium subtropicum He 1827 (BJFC 016294, holotype). A. Basidiomes. B. Basidiospores. C. Basidia. D. Basidioles. E. Pseudocystidia. F. Generative hyphae from subiculum. Scale bars: A = 1 cm; B–F = 10 µm.

Fig. 1. Phylogenetic tree obtained from maximum parsimony analysis of ITS-LSU sequence data of Stereaceae. Branches are labelled with parsimony bootstrap values (≥ 70 %, first), maximum likelihood bootstrap values (≥ 70 %, middle) and Bayesian posterior probabilities (≥ 0.95, last). Type species of each genus are marked with an asterisk “*”. New taxa are shown in bold with type specimens marked with a number sign “#”.