Dimelaena altissima (H. Magn.) M. Ai & Xin Y. Wang, comb. nov. MycoBank no. 841532 Rinodina altissima H. Magnusson (1940: 155). Type:— CHINA. Gansu Province: Taben-Buluk, 4000 m, 1931, Birger Bohlin 35a (S, holotype!). Rinodina altissima var. exalbescens H. Magnusson (1940: 156); Dimelaena oreina var. exalbescens (H. Magn.) Wei (1991: 89). Type:— CHINA. Gansu Province: Ehr-tao-ch’uan (Nan-shan), at about 4200 m, on rock facing the South, 5 January 1932, Birger Bohlin 74b (S, holotype !). (Fig. 3) Thallus crustose, thick or thin, closely attached to the substrate, areolate at center and radiate-plicate at margin, areolae 0.55–0.90 mm wide, sometimes darkened around the areolae; marginal lobes flat and narrow, Apothecia cryptolecanorine to lecanorine, immersed, often touching each other, irregularly rounded, 0.18–0.63 mm in diam., disc black, disc margin not obvious or absent; epihymenium brown; hymenium hyaline, 60–80 μm high, inspersed with oil droplets; hypothecium hyaline, 80–135 μm high; asci clavate, Bacidia - type, 8-spored; ascospores brown, 1-septate, thin walled, 8.5–13 × 4.5–7 μm, markedly constricted at septum when mature. Pycnidia rare, immersed; conidia bacilliform, 6 × 1 μm. Chemistry: Usnic and gyrophoric acids, sometimes with hypostictic, stictic and norstictic acids. Ecology and distribution: This species usually grows on exposed siliceous rock, at elevations of 2737–4805 m. Distributed in Sichuan, Xizang, Qinghai and Gansu provinces in China (Fig. 2). Notes: Dimelaena altissima is characterized by having a plane lobed thallus margin, tightly attached to the substrate, innate and irregularly rounded apothecia. It differs from D. oreina by lacking convex marginal lobes and well-defined apothecia margins. Sheard & Ahti (1975) regarded Rinodina altissima as a synonym for D. oreina due to similar anatomical features, and because morphological characters did not correlate with chemical ones. Obermayer et al. (2004) agreed with this treatment. Now, however, morphological differences, supported by molecular data, lead to the division of these species. There is no reason to subsume several chemotypes within a species. Gyrophoric acid was detected in D. altissima. In addition, stictic acid and hypostictic acid were detected in some specimens. Additional specimens examined. CHINA. Gansu Province: Sunan Co., on the route from Sunan to Qilian, 3479 m, 38°39′16.58″N, 99°29′30.87″E, 30 May 2018, Wang Lisong et al. 18-59774; Sunan Co., on the route from Sunan to Qilian, 3928 m, 38°37′45.45″N, 99°28′31.76″E, 30 May 2018, Wang Lisong et al. 18-58855; Subei Co., Nanshan Mt., near 29th Mengke Glacier, 3392 m, 39°13′52.53″N, 95°24′18.40″E, 23 May 2018, Wang Lisong et al. 18-58543 . Qinghai Province: Huangyuan Co., on the route to Qinghai Lake, 2737 m, 36°45′54.72″N, 101°08′05.79″E, 18 May 2018, Wang Lisong et al. 18-59138; Huzhu Co., beside Weibei road, 3060 m, 37°00′26.52″N, 102°08′16.81″E, 31 May 2018, Wang Lisong et al. 18-59930; Qilian Co., on the route from Sunan to Qilian, 2807 m, 38°13′44.92″N, 99°59′48.79″E, 30 May 2018, Wang Lisong et al. 18-59878; Zaduo Co., 4090 m, 32°52′43.78″N, 95°20′28.55″E, 20 September 2020, Wang Lisong et al. 20-68622 . Sichuan Province: Rangtang Co., Haizishan, 4237 m, 32°20′02.40″N, 101°25′00.23″E, 9 June 2020, Wang Lisong et al. 20-66696. Xizang Province: Cuoqin Co., 4805 m, 31°11′37.70″N, 85°03′32.37″E, 20 July 2019, Wang Lisong et al. 19-65370; Kangma Co., Nanni Vil., 4136 m, 28°46′16.29″N, 89°38′48.64″E, 24 July 2019, Wang Xinyu et al. xy19-1416; Zhongba Co., Zhuzhu Vil., 4647 m, 29°47′17.16″N, 83°54′09.76″E, 25 July 2019, Wang Lisong et al. 19-63935; Zhongba Co., Zhuzhu Vil., 4650 m, 29°47′17.29″N, 83°54′09.74″E, 25 July 2019, Wang Lisong et al. 19-63938; Zhongba Co., Zhuzhu Vil., 4639 m, 29°47′16.57″N, 83°54′09.61″E, 25 July 2019, Wang Lisong et al. 19-63927; Kangma Co., Nanni Vil., 4120 m, 28°46′14.32″N, 89°38′48.78″E, 24 July 2019, Wang Xinyu et al. XY19-2343; Yadong Co., Kangbu Vil., 4039 m, 27°45′41.83″N, 88°58′58.41″E, 27 July 2019, Wang Xinyu et al. XY19-1719 ., Published as part of Ai, Min, Zhong, Qiuyi, Scheidegger, Christoph, Wang, Lisong & Wang, Xinyu, 2022, Revision of Dimelaena Norman (Caliciaceae, Ascomycota) species containing usnic acid reveals a new species and a new combination from China, pp. 259-272 in Phytotaxa 574 (4) on pages 264-265, DOI: 10.11646/phytotaxa.574.4.1, http://zenodo.org/record/7389058, {"references":["Magnusson, A. H. (1940) Lichens from central Asia I. In: Hedin, S. (Ed.) Reports Scientific Exped. Nort-West provinces of China (the SinoSwedish Expedition). Publication 13, XI. Botany 1, Stockholm, Aktiebolaget Thule, pp. 1 - 168.","Wei, J. C. (1991) An Enumeration of Lichens in China. International Academic Publishers, Beijing. 278 pp.","Obermayer, W., Blaha, J. & Mayrhofer, H. (2004) Buellia centralis and chemotypes of Dimelaena oreina in Tibet and other Central-Asian regions. Symbolae Botanicae Upsaliensis 34: 327 - 342.","Sheard, J. W. & Ahti, T. (1975) The lichen Dimelaena oreina in east-central Asia, with notes on its typification and chemical races. Annales Botanici Fennici 12: 89 - 92."]}