Species diversity and taxonomy of Vararia (Russulales, Basidiomycota) with descriptions of six species from Southwestern China Author Deng, Yinglian https://orcid.org/0000-0002-8220-508X The Key Laboratory of Forest Resources Conservation and Utilization in the South-west Mountains of China Ministry of Education, Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Southwest China, Yunnan Provincial Key Laboratory for Conservation and Utilization of In-forest Re-source, Southwest Forestry University, Kunming 650224, China Author Jabeen, Sana https://orcid.org/0000-0001-8839-7716 College of Biodiversity Conservation, Southwest Forestry University, Kunming 650224, China Author Zhao, Changlin https://orcid.org/0000-0002-8668-1075 The Key Laboratory of Forest Resources Conservation and Utilization in the South-west Mountains of China Ministry of Education, Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Southwest China, Yunnan Provincial Key Laboratory for Conservation and Utilization of In-forest Re-source, Southwest Forestry University, Kunming 650224, China fungichanglinz@163.com text MycoKeys 2024 2024-03-22 103 97 128 http://dx.doi.org/10.3897/mycokeys.103.118980 journal article http://dx.doi.org/10.3897/mycokeys.103.118980 1314-4049-103-97 9B8DCBBA226C5B1BAFBE15B6C2B4E067 Vararia fissurata Y.L. Deng & C.L. Zhao sp. nov. Figs 3 , 4 Holotype. China. Yunnan Province, Yuxi, Xinping County, the Ancient Tea Horse Road, 23°57'10"N , 101°30'41"E , altitude 2600 m a.s.l., on the trunk of angiosperm, leg. C.L. Zhao, 21 August 2018, CLZhao 8171 (SWFC). Figure 3. Basidiomata of Vararia fissurata (holotype). Scale bars: 1 cm ( A ); 1 mm ( B ). Etymology. Fissurata (Lat.): referring to the cracking hymenial surface. Figure 4. Microscopic structures of Vararia fissurata (holotype) A a section of hymenium B basidiospores C basidia D basidioles E gloeocystidia subulate F gloeocystidia subglobose G dichohyphae. Scale bars: 10 µm ( A-G ). Description. Basidiomata annual, resupinate, adnate, pruinose, brittle, without odor or taste when fresh, up to 12 cm long, 2.5 cm wide, and 100 µm thick. Hymenial surface smooth, white to olivaceous buff when fresh, and olivaceous buff upon drying, sparsely and deeply cracked with age. Sterile margin distinct, white, and up to 2 mm wide. Hyphal system dimitic, generative hyphae with clamp connections, colorless, thin-walled, moderately branched, interwoven, 2-3 µm in diameter; IKI-, CB-, tissues unchanged in KOH. Dichohyphae predominate, yellowish, capillary, frequently branched, 1.5 µm in diameter, thick-walled, dichotomously to irregularly branched with main branches and acute tips, weakly to moderately dextrinoid in Melzer's reagent, CB-, tissues unchanged in KOH; subhymenial hyphae densely covered by a lot of bulk crystals. Gloeocystidia empty or filled with refractive flocculent matter, two types: (1) Gloeocystidia subglobose, colorless, thin-walled, smooth, 11-23 x 6-12 µm ; (2) Gloeocystidia subulate, usually containing refractive materials; slightly constricted at the neck, colorless, thin-walled, smooth, 25.5-43 x 7-11 µm . Basidia cylindrical, with four sterigmata and a basal clamp connection, 20-27 x 4-8 µm ; basidioles dominant, in shape similar to basidia but slightly smaller. Basidiospores ellipsoid to broadly ellipsoid, colorless, thin-walled, smooth, IKI-, CB-, 5-10 x 3-7 µm , L = 7.37 µm , W = 5.22 µm , Q = 1.38-1.44 (n = 150/5). Additional specimens examined ( paratypes ). China . Yunnan Province , Yuxi , Xinping County , the Ancient Tea Horse Road , 23°57'10"N , 101°30'41"E , altitude 2600 m a.s.l. , on fallen angiosperm branch, leg. C.L. Zhao , 13 January 2018 , CLZhao 5218 (SWFC); Puer , Zhenyuan County , Heping Town , Damoshan , 23°56'21"N , 101°25'32"E , altitude 2240 m a.s.l. , on fallen angiosperm branch, leg. C.L. Zhao , 16 January 2018 , CLZhao 6070 (SWFC); Dali , Weishan Country , Qinghua Town , Green Peacock Nature Reserve , 25°23'35"N , 100°31'39"E , altitude 1500 m a.s.l. , on the fallen branch of angiosperm, leg. C.L. Zhao , 18 July 2022 , CLZhao 22538 (SWFC); Puer , Jingdong County , Wuliangshan National Nature Reserve , 24°34'45"N , 100°830'03"E, altitude 2000 m a.s.l. , on fallen angiosperm branch, leg. C.L. Zhao , 6 October 2017 , CLZhao 4614 (SWFC); 6 January 2019 , CLZhao 9618, CLZhao 9668 and CLZhao 9697 (SWFC); Dali, Nanjian County, Lingbaoshan National Forest Park, 24°78'26"N, 100°51'30"E , altitude 2500 m a.s.l. , on fallen angiosperm branch, leg. C.L. Zhao , 9 January 2019 , CLZhao 10118, and CLZhao 10181 (SWFC) .