A new corticioid fungus, Alloexidiopsis sinensis (Auriculariales, Basidiomycota), in China, evidenced by morphological characteristics and phylogenetic analyses Author Dong, Junhong 0000-0001-8740-0805 College of Forestry, Southwest Forestry University, Kunming 650224, P. R. China fungijunhondong@163.com Author Gu, Zirui 0000-0003-1476-9040 College of Forestry, Southwest Forestry University, Kunming 650224, P. R. China fungiziruig@163.com Author Wang, Yuyun 0009-0007-7011-0327 College of Forestry, Southwest Forestry University, Kunming 650224, P. R. China fungiyuyunw@163.com Author Shi, Yinmei 0000-0002-5962-7049 Xianggelila Forestry and Grassland Bureau, Diqing, 674499, P. R. China 17708878113@163.com Author Zhao, Changlin 0000-0002-8668-1075 College of Forestry, Southwest Forestry University, Kunming 650224, P. R. China fungichanglinz@163.com text Phytotaxa 2024 2024-07-05 658 3 227 239 http://dx.doi.org/10.11646/phytotaxa.658.3.1 journal article 10.11646/phytotaxa.658.3.1 1179-3163 13217680 Alloexidiopsis sinensis J.H. Dong & C.L. Zhao , sp. nov. Figs. 3 , 4 , 5 MycoBank no.: MB 852467 Etymology : — sinensis (Lat.) : referring to the type locality ( China ). Diagnosis: — Differs from other species of Alloexidiopsis in the yellowish-brown to rose to slightly purple hymenial surface, generative hyphae thin- to thick-walled, allantoid basidiospores (14.5–23 × 4.5–6.5 µm). Holotype : — CHINA . Yunnan Province , Chxiong, Zixishan National Forest Park, 25°01′N , 101°22′E , elev. 2000 m , on the trunk of Quercus , 2 July 2018 , CLZhao 7343 (SWFC!). Basidiomata : — Annual, resupinate, adnate, membranaceous, becoming hard brittle upon drying, very hard to separate from substrate, without odor or taste when fresh, up to 15 cm long, 5 cm wide, 0.2–1 mm thick. Hymenial surface grandinoid, covered by spines, spines 7–10 per mm, up to 0.1 mm long, cream to buff when fresh, turning to yellowish-brown to rose to slightly purple upon drying. Sterile margin distinct, slightly buff, and up to 1 mm wide. FIGURE 3. Basidiomata of Alloexidiopsis sinensis (A, B) CLZhao 7343 (holotype); (C, D) CLZhao 6775; (E, F) CLZhao 16935. Bars: A, C, E= 1 cm; B, D, F= 1 mm. Hyphal structure : — Hyphal system monomitic, generative hyphae with clamp connections, hyaline, thin- to thick-walled, frequently branched, interwoven, 2–3 μm in diameter; IKI–, CB–, tissues unchanged in KOH. Hymenium : — Cystidia cylindrical with an obtuse apex, 11.5–15.5 × 3–5.5 µm, with a clamp connection at the base; cystidioles absent. Hyphidia arising from generative hyphae, nodulose or branched, colorless, thin-walled, 1.5–3.5 μm in diameter. Basidia ellipsoid to ovoid, longitudinally septate, two to four-celled, 16–22 × 7.5–10 µm; basidioles dominant, similar to basidia in shape, but slightly smaller. Basidiospores: — Allantoid, colorless, smooth, thin-walled, with 1–2 oil drops, IKI–, CB–, 14.5–23(–25) × (4.2–)4.5–6.5(–6.7) µm, L = 18.38 μm, W = 5.38 µm, Q = 3.13–3.15 (n = 210/7). Type of rot : — White rot. FIGURE 4. Microscopic structures of Alloexidiopsis sinensis (holotype, CLZhao 7343). (A) Basidiospores; (B) Basidia; (C) Basidioles; (D) Cystidia; (E) Hyphidia; (F) Part of the vertical section of hymenium. Bars: A–F = 10 μm. FIGURE 5. Sections of hymenium of Alloexidiopsis sinensis (holotype, CLZhao 7343). Scale bars: A, C, E = 20 μm; B, D, F = 10 μm, 10 × 100 Oil. Additional specimens examined : — CHINA . Yunnan Province , Puer, Jingdong County, Wuliangshan National Nature Reserve, 24°22′N , 100°45′E , elev. 2200 m , on the branch fallen of angiosperm, 5 October 2017 , CLZhao 4146, 4 January 2019 , CLZhao 9274, CLZhao 9283 (SWFC!); Yuxi, Xingping county, Tea Horse Ancient Road Scenic Spot, 22°58′N , 101°05′E , elev. 1500 m , on the branch fallen of angiosperm, 13 Janurary 2018, CLZhao 5171, CLZhao 5232, CLZhao 5309, CLZhao 5316, CLZhao 5323, CLZhao 5362, 21 August 2018 , CLZhao 8219 (SWFC!); Chxiong, Zixishan National Forest Park, 25°01′N , 101°22′E , elev. 2000 m , on the branch fallen of angiosperm, 30 June 2018 , CLZhao 6775, CLZhao 6777, 1 July 2018 , CLZhao 7105, CLZhao 7292(SWFC!); Wenshan, Pingba Town, Wenshan National Nature Reserve, 23°18′N , 104°16′E , elev. 1650 m , on the branch fallen of angiosperm, 28 July 2019 , CLZhao 16935, CLZhao 16947, CLZhao 16948, CLZhao 16949, CLZhao 16964, CLZhao 17016, CLZhao 17020, CLZhao 17064, CLZhao 17083, CLZhao 17234 (SWFC!).