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

Figure 7e-h

Etymology.

The name " Lecaimmeria lygaea " refers to the dark appearance of the thallus.

Type.

China. Tibet: Changdu City, Mangkang County, Luoni Village , 4127 m elev., 29°56'N, 98°33'E, on rock, 24 Sept 2020, Li-Song Wang et al. 20-69072 (KUN-holotype) .

Description.

Thallus areolate, dark red-brown, dark brown, continuous; areolae 0.5-1.0 mm across, flat, epruinose, irregular pentagonal, sometimes rectangular, fissures between areolae often filled with black prothallus; margin black, thinly pruinose; prothallus black, developed between areolae, also distinct in the margin. Upper cortex ca. 20.0 μm thick, orange-brown; epinecral layer ca. 15.0 μm thick; algal layer ca. 50.0 μm thick, cells 7.0-13.0 μm in diam., round. Apothecia frequent, round, crowded, immersed, 0.2-0.8 mm in diam.; disc red-brown, flat, or concave, epruinose; margin black, moderately thick, pruinose, raised. Hymenium 75.0-93.0 μm thick, colourless; paraphyses ca. 2.0 μm wide, simple, unbranched, not anastomosing; epihymenium 25.0-38.0 μm thick, orange brown; plectenchyma ca. 7.0 μm thick; subhymenium 20.0-25.0 μm thick, colourless; hypothecium brown Asci Porpidia -type, cylindrical, eight-spored; ascospores 12.5-20.0 × 5.0-7.5 μm in diam., ellipsoid, halonate. Conidiomata immersed, stellate, black, margin pruinose; conidia 5.0 × 1.0 μm, bacilliform.

Chemistry.

Thallus K-, C-. Medulla I+ violet. Unknown fatty acid by TLC.

Ecology and distribution.

In China, growing on sandstone at elevations of 4000-4200 m in the alpine zone. This species is known from the Tibet Region of China.

Notes.

Lecaimmeria lygaea is characterised by its dark brown thallus, black margin of its areolae, black prothallus which fills the fissures between areolae, dark orange apothecia and its orange brown epihymenium. Lecaimmeria cupreoatra and L. mehadiana are similar to L. lygaea , but L. cupreoatra has a discontinuous thallus, with each areola surrounded by black prothallus, dark red-brown to black-brown apothecia without a margin. Lecaimmeria mehadiana has areolae with a white margin, black-brown apothecia, brown epihymenium and contains 4-O-demethylplanaic acid. The phylogenetic results show that Lecaimmeria tibetica is the sister species to L. lygaea. They are similar in chemistry, but differ in its orange-brown thallus and dark orange brown apothecia.

Specimens examined (KUN).

China. Tibet: Changdu City, Mangkang Co., Luoni Village , 4099 m elev., 29°56'N, 98°33'E, on rock, 2020, Li-Song Wang et al. 20-69054, 4131 m elev., Li-Song Wang et al. 20-69070, 4127 m elev., Li-Song Wang et al. 20-69072, 4095 m elev., Li-Song Wang et al.20-69053 .

Figures

Figure 7. Lecaimmeria botryoides (a-d KUN 20 - 66730): a-b thallus c apothecial anatomy. L. lyagea (e-h KUN 20 - 69070): e-f thallus g apothecial anatomy h scospores. Scale bars: 1 mm (a-b, e-f); 20 μm (c, g); 10 μm (d, h).