Immersaria aurantia C.M. Xie & Li S. Wang, 2022

Xie, Cong-Miao, Wang, Li-Song, Zhao, Zun-Tian, Zhang, Yan-Yun, Wang, Xin-Yu & Zhang, Lu-Lu, 2022, Revision of Immersaria and a new lecanorine genus in Lecideaceae (lichenised Ascomycota, Lecanoromycetes), MycoKeys 87, pp. 99-132 : 99

Immersaria aurantia C.M. Xie & Li S. Wang sp. nov.

Figure 4f-j

Etymology.

The name " Immersaria aurantia " refers to the orange thallus.

Type.

China. Tibet: Sajia Co., Mula Village , 4752 m elev., 28°40'N, 88°45'E, on rock, 28 Jun 2019, Xin-Yu Wang et al. XY19-1814 (KUN-holotype) .

Description.

Thallus areolate, orange, dark orange, pale orange to pale red-brown, continuous; areolae 0.7-1.3 mm across, flat, epruinose, irregular; margin thin pruinose; prothallus not seen. Upper cortex 25.0-45.0 μm thick, orange; epinecral layer (12.0-) 37.0-63.0 μm thick, uneven; algal layer 50.0-93.0 μm thick, cells 5.0-15.0 × 5.0-10.0 μm in diam., round to ellipsoid. Apothecia frequent, scattered, immersed or isolated from areolae, 0.3-1.3 mm in diam.; disc black, flat or concave, sometimes pruinose; margin reduced. Exciple sometimes developed, ca. 30.0 μm wide, brown. Hymenium 55.0-83.0 μm thick, colourless; paraphyses 2.0-3.0 μm wide, only branched and anastomosing at apex; epihymenium ca. 20.0 µm thick, green or green-brown; subhymenium colourless, not distinct or absent; hypothecium brown. Asci Porpidia -type, cylindrical, eight-spored; ascospores 8.0-15.0 × 5.0-7.5 μm in diam., ellipsoid, halonate. Conidiomata rare, immersed, oblate, black, margin white; conidia 7.5 × 1.0 μm, bacilliform.

Chemistry.

Thallus K-, C-. Medulla I + violet. Chemotype Ⅰ: Confluentic acid, often accompanied with 2'-O-methylmicrophyllinic acid. Chemotype Ⅱ: Planaic acid. Chemotype Ⅲ: none (rare).

Ecology and distribution.

In China, growing on rock at elevations of 3900-4300 m in the alpine zone. This species is known from Qinghai, Sichuan Province and Tibet of China.

Notes.

Immersaria aurantia is characterised by its distinct orange, irregular areolae and the mostly green epihymenium. Immersaria athroocarpa and I. venusta are similar to I. aurantia , but I. athroocarpa differs in the convex, regularly polygonal areolae and the more crowded apothecia; I. venusta differs in having yellow-brown, often rusty, cracked areolae and flat apothecia. Additionally, confluentic acid and planiaic acid do not appear simultaneously in Immersaria aurantia , whereas I. venusta always contains both compounds.

Specimens examined (KUN).

China. Qinghai Province: Banma Co., 3933 m elev., 32°40'N, 100°48'E, on rock, 2020, Li-Song Wang et al. 20-66886, 3932 m elev., Li-Song Wang et al. 20-66897; Jiuzhi Co. , Baiyu Village , 4285 m elev., 33°14'N, 100°58'E, Li-Song Wang et al. 20-67809 . Sichuan Province: Rangtang Co., Mt. Haizi , 4223 m elev., 32°20'N, 101°25'E, on rock, 2020, Li-Song Wang et al. 20-66701, 4229 m elev., Li-Song Wang et al. 20-66693, 4217 m elev., Li-Song Wang et al. 20-66680, 4221 m elev., Li-Song Wang et al. 20-66692 . Tibet: Changdu City, Mangkang Co., Luoni Village , 4145 m elev., 29°56'N, 98°33'E, on rock, 2020, Li-Song Wang et al. 20-69091, 4138 m elev., Li-Song Wang et al. 20-69091, 20-69094; Gatuo Town , 29°39'N, 98°35'E, 3831 m elev., Li-Song Wang et al. 20-69114, 3850 m elev., Li-Song Wang et al. 20-69122; Gongga Co. , Jiangtang Town , 29°12'N, 90°38'E, 2019.7.23, 4560 m elev., Xin-Yu Wang et al. XY 19-1287, 4556 m elev., XY19-1290; Sajia Co. , Mula Village , 28°40'N, 88°45'E, 2019.7.28, 4752 m elev., Xin-Yu Wang et al. XY19-1814; Angren Co. , Kerangla , 29°19'N, 87°01'E, 4530 m elev., Li-Song Wang et al. 19-63635 .

Figures

Figure 4. Immersaria athroocarpa (a-e SDNU 20190227): a-b thallus c apothecial anatomy d ascus e ascospores. I. aurantia (f-j KUN XY 19 - 1290): f-g thallus h apothecial anatomy i ascus j ascospores. Scale bars: 1 mm (a-b, f-g); 20 μm (c, h); 10 μm (d-e, i-j).