Ochrolechia leigongshanensis Zheng & Fu, 2025

Ochrolechia leigongshanensis Zheng & Fu sp. nov.

Fig. 4 View Figure 4

Remark.

Ochrolechia leigongshanensis is distinguished by the presence of soralia and the thallus contains gyrophoric acid, lecanoric acid and atranorin. In most apothecia, a ring of smooth, salmon-pink tissue is visible along the inner edge of the apothecial margin.

Type.

China • Guizhou, Qiandongnan Prefecture, Leigongshan Nat. Res , on bark, 1666 m elev., 2023, B. Liu and Z. Yang, LGS 186 ( KUN-L 96621 , holotype) .

Etymology.

The new species has been named after Leigongshan, the locality where it was collected.

Holotype.

KUN-L 96621

Description.

Thallus greyish-white, thin, verruculose, dull; prothallus indistinct; isidia absent, with a few white soralia.

Sexual morph. Apothecia frequent, scattered or crowded, sessile, round, 1.9–2.7 mm diam.; disc plane, pale pink, epruinose to lightly pruinose, margins thick, clearly verrucose, higher than disc, shiny, concolorous with the thallus, a ring of smooth, salmon-pink tissue is distributed along the inner edge of the apothecial margin in most apothecia. Pycnidia are absent. Hymenium hyaline and colourless, 168–180 μm high; paraphyses are branched, densely aggregated; epihymenium dark brown (the colour disappears in a 10 % KOH solution), 10–13 μm high; hypothecium inconspicuous; coccoid green alga, algae forming a continuous layer in the margin and in scattered clumps below the hypothecium. Asci narrowly clavate, 4–8 - spored, 208–230 × 25–33 μm (n = 10). Ascospores hyaline, broadly ellipsoid, aseptate, (62) 64–69 (70) × (27) 28–33 (34) μm (n = 30).

Chemistry.

Thallus contains gyrophoric acid and lecanoric acid and atranorin; ascomata contain gyrophoric acid, lecanoric acid ( TLC). Thallus cortex: K + pale yellow, C + red, KC + red; medulla: C –; apothecia cortex: K + yellow-green, C + red, KC + red to yellow-green; medulla: C –; disc: C + red; thallus UV –.

Material examined.

China • Guizhou Province, Qiandongnan Prefecture, Leigongshan National Nature Reserve , 26°22'42.92"N, 108°11'42.51"E, 1666 m elev., on bark, 27 October, 2023, Bo Liu and Ze Yang, LGS 186 ( KUN-L 96621 , holotype) GoogleMaps .

Notes.

Phylogenetic analysis places this species in a distinct, but weakly supported clade, sister to O. akagiensis and O. subrosella . Nucleotide comparison shows that O. leigongshanensis (LGS 186) differs from O. akagiensis (Hara Kojiro: 0007) by 8.07 % (39 / 483 bp) in the ITS region and from O. subrosella (LGS 176) by 8.49 % (41 / 483 bp) in the ITS sequence and 1.45 % (10 / 688 bp) in the mtSSU sequence. Moreover, both O. subrosella and O. akagiensis lack soralia and atranorin ( Ren 2017) and a ring of salmon-pink tissue is absent from the inner edge of the apothecial margin. O. akagiensis produces isidia ( Park et al. 2019).

According to the description of O. trochophora var. trochophora in the identification key by Ren (2017), O. leigongshanensis is similar to this taxon, but the latter lacks atranorin, without soredia and the excipular ring of salmon disc-like tissue is not visible ( Brodo 1991). Judging by the description of O. montana in Brodo (1991), O. leigongshanensis is also similar to this taxon, but O. montana lacks soredia and has smaller apothecia ( 0.7–1.8 mm in diameter). Chemically, it produces gyrophoric acid and a trace of lecanoric acid as major substances, sometimes along with trace of an unidentified minor compound.