Lobothallia benzilanensis Lun Wang & Y. Y. Zhang, 2025

Wang, Lun, Feng, Yi-Shan, Wang, Li-Song, Wang, Xin-Yu & Zhang, Yan-Yun, 2025, An overview of the genus Lobothallia (lichenized Ascomycota, Megasporaceae) in China, MycoKeys 125, pp. 205-244 : 205-244

Lobothallia benzilanensis Lun Wang & Y. Y. Zhang sp. nov.

Fig. 2

Etymology.

The specific epithet refers to Benzilan Town, the type locality of this species.

Diagnosis.

Thallus non-lobate, areoles dispersed to continuous, tightly adnate to the substrate; upper surface pruinose, off-white, partially with orangish tinge; apothecia cryptolecanorine to lecanorine; containing norstictic, cryptostictic, and connorstictic acids.

Holotype.

China • Yunnan Prov.: Deqin Co., Benzilan Town, 28°11'35.79"N, 99°21'07.65"E, Along Jinshajiang River side , alt. 2108 m, on rock, 19 August 2018, Li-Song Wang et al. 18-60350 ( KUN-L 63843 ) .

Description.

Thallus areolate, non-lobate, tightly adnate to the substrate. Areoles dispersed to continuous, central areoles irregular, 0.5–1 mm wide, marginal areoles usually larger than the center, 3–10 mm wide, cracked; distant simple areoles circular, 0.5–3 mm wide. Upper surface plane to slightly convex, pruinose, off-white, with orangish tinge. Upper cortex paraplectenchymatous, 30–60 µm thick, inspersed with brown to dark brown granules (soluble in K); epinecral layer gelatinous, 10–20 µm thick, with hyaline crystals and dark brown granules (insoluble in K). Algal layer 50–125 µm thick, discontinuous; photobiont chlorococcoid, cells 8–20 µm diameter. Medulla opaque, filled with gray-black granules (not or partially soluble in K). Lower cortex absent.

Apothecia common (1–4 per areole), orbicular, 0.3–1 mm diameter, initially cryptolecanorine, becoming lecanorine and elevated above areoles at maturity, not constricted at base; disc slightly concave to plane, matt, black, pruinose; apothecial margin indistinct when young, becoming prominent ( 0.05–0.15 mm wide) during development, receding with disc expansion. Exciple absent or narrow, not exceeding 50 μm. Epithecium, hymenium and subhymenial layers combined 175–200 µm high; epithecium 10–20 µm high, containing hyaline crystals; epihymenium with brown granules (soluble in K) and black granules (insoluble in K), N-; hymenium 100–120 µm high, hyaline, I + blue; subhymenial layers 50–75 µm high, hyaline, I + blue; algal layer sparse below hypothecium; paraphyses simple, septate, non-moniliform, with 1–3 uppermost cells wider than the basal cells, 4–6 μm wide (basal cells ca. 2 μm wide); asci clavate, Aspicilia - type, 8 - spored, 70–80 × 18–25 µm; ascospores simple, hyaline, broadly ellipsoid, (10.0 -) 11.5–12.4 – 13.2 (- 14.0) × (8.0 -) 7.9–8.6 – 9.3 (- 10.0) µm (n = 36), l / w ratio (1.2 -) 1.3–1.4 – 1.5 (- 1.7), wall ca. 1 µm thick. Pycnidia few, punctiform, plane to slightly convex, 0.05–0.2 mm diameter; ostiole brown to dark brown; conidia bacilliform, hyaline, 4–6 × 1 µm.

Chemistry.

Cortex K + yellow, P-; Medulla K + yellow to orangish red, P + yellow, C-, KC-; norstictic, cryptostictic and connorstictic acids detected in TLC.

Habitat and distribution.

Growing on the exposed calcareous rock. Currently only known from the town of Benzilan, Yunnan, China.

Notes.

This species is similar to Lobothallia gangwondoana in having a non-lobate thallus with dispersed areoles. However, L. gangwondoana differs in its larger areoles, epruinose and slightly brownish-gray to cacao-gray upper surface (vs. pruinose, off-white with light orangish tinge in L. benzilanensis ), epruinose apothecial disc (vs. pruinose), and in the lack of cryptostictic and connorstictic acids ( Kondratyuk et al. 2020).

Additional specimens examined.

China • Yunnan Prov.: Diqing Tibetan Autonomous Prefecture, Shangri-La City, near Jinshajiang River in Benzilan Vil. , 28°11'35.79"N, 99°21'07.65"E, alt. 2108 m, on rock, 19 August 2018, Li-Song Wang et al. 18-60354 ( KUN-L 63847 ) .

Figures

Figure 2. Lobothallia benzilanensis (KUN-L 63843, holotype). A. Thallus; B, C. Apothecia; D. Punctiform pycnidia; E. Section of thallus; F. Upper cortex and epinecral layer (LCB); G. Vertical section of apothecium; H. Asci and ascospores; I. Conidia; J, K. Paraphyses (LCB after K). Scale bars: 0.5 mm (A); 0.2 mm (B, C, D); 100 µm (E); 50 µm (G); 10 µm (F, H); 5 µm (I, J, K).