Lecaimmeria orbicularis C.M. Xie & Lu L. Zhang, 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

Lecaimmeria orbicularis C.M. Xie & Lu L. Zhang sp. nov.

Figure 9a-e

Etymology.

The name " Lecaimmeria orbicularis " refers to the round shape of the apothecia.

Type.

China. Sichuan Province: Rangtang Co., Gangmuda Village , 3800 m elev., 32°18'N, 101°3'E, on rock, 7 Sept 2020, Li-Song Wang et al. 20-66753 (KUN-holotype) .

Description.

Thallus areolate, red-brown, rarely orange-brown, continuous; areolae 0.2-1.0 mm across, flat, occasionally wrinkled, tending to rectangular, fissures between areolae often filled with black prothallus, margin pruinose; prothallus black, developed between areolae, also distinct in the margin. Upper cortex 42.0-58.0 μm thick, brown; epinecral layer 5.0-20.0 μm thick; algal layer 70.0-113.0 μm thick, cells 10.0-15.0 × 7.5-10.0 μm in diam., ellipsoid to round. Apothecia frequent, scattered, immersed or isolated from areolae, 0.5-1.3 mm in diam.; disc red-brown, flat, round, epruinose; margin white, slightly raised. Hymenium 75.0-113.0 μm thick, colourless; paraphyses ca. 2.0 μm wide, simple, unbranched, not anastomosing; epihymenium 17.5-30.0 μm thick, orange; plectenchyma 5.0-15.0 μm thick; subhymenium 30.0-63.0 μm thick, colourless; hypothecium brown. Asci Porpidia -type, cylindrical, eight-spored; ascospores 12.5-15.0 × 5.0-6.0 μm, ellipsoid, halonate. Conidiomata not seen.

Chemistry.

Thallus K-, C-. Medulla I+ violet. None.

Ecology and distribution.

In China, growing on granite or sandstone at elevations of 3700-4200 m in the alpine zone. This species is known from Qinghai and Sichuan Provinces of China.

Notes.

Lecaimmeria orbicularis is characterised by its orange brown thallus, neatly arranged areolae and round, flat apothecia. Lecaimmeria botryoides is similar to L. orbicularis (see notes for L. botryoides ). Lecaimmeria mongolica might be confused with L. orbicularis due to its large apothecia with a white margin, but differs in its red-brown thallus and distribution in steppes. The red-brown thallus of Lecaimmeria cupreoatra resembles that of L. orbicularis , but differs in the black margin of its apothecia and its distinct black prothallus between areolae.

Specimens examined (KUN).

China. Qinghai Province: Jiuzhi Co., Nianbaoyuze, 4200 m elev., 33°14'N, 100°58'E, on rock, 2020, Li-Song Wang et al. 20-66811, 20-66829, 20-66801, 20-66826A, 20-66821, 20-66805, 20-66833, 20-66817, 20-66841; Banma Co. , Nianbaoyuze , 3930 m elev., 32°40'N, 100°48'E, Li-Song Wang et al. 20-66909, 20-66908, 20-66896, 20-66886B, 20-66899, 20-66935, 20-66943; Zhiqingsongduo Town , 3712 m elev., 33°24'N, 101°25'E, Li-Song Wang et al. 20-66965; Suohurima Village , 4029 m elev., 33°23'N, 100°57'E, Li-Song Wang et al. 20-66979 . Sichuan Province: Rangtang Co., Gangmuda Village, 3800 m elev., 32°18'N, 101°3'E, on rock, 2020, Li-Song Wang et al. 20-66753, 20- 66750, 3793 m elev., Li-Song Wang et al. 20-66747, Shangrangtang Village , 3730 m elev., 32°16'N, 101°21'E, Li-Song Wang et al. 20-66743 .

Figures

Figure 9. Lecaimmeria orbicularis (a-e KUN 20 - 66753): a-b thallus c apothecial anatomy d ascus (Lugol's iodine) e ascospores. L. qinghaiensis (f-i KUN 20 - 68696): f-g thallus h apothecial anatomy i ascus. Scale bars: 1 mm (a-b, f-g); 20 μm (c, h); 10 μm (d, e, i).