Gyalolechia farinosa D. L. Niu 2025, sp. nov.

Gyalolechia farinosa D. L. Niu sp. nov. (FIGURE 2A–F) Fungal Names No.: FN 571857 Diagnosis: Gyalolechia farinosa has a powdery, rough upper surface with uneven pruisa, an upper cortex with numerous crystals, and ascospores one-septate, ellipsoid or broader ellipsoid, 11.0–15.0 × 4.0–5.0 µm. Type: China, Ningxia, Helanshan National Natural Reserve, Suyukou, on soil, 1347 m alt. 38°42’47” N, 106°0’35.4” E, 6 Jul 2017, D. L. Niu 17-0573-1 (NXAC – holotype). GenBank Accession no.: PP204166. Thallus crustose, consists of widely scattered to densely crowded areoles, without distinct marginal lobes. Areoles up to 1.6 mm across. Upper surface powdery, rough, pale yellow to gray-white with uneven pruisa. Upper cortex pale yellow to brown -yellow, with the presence of a large number of crystals, 12.5–37.5 µm thick. Algal layer continuous, 75.0–80.0 µm thick, with algal cells spherical, 12.5–17.5 µm in diameter. Medulla white, 81.5–143.5 µm thick. Lower cortex absent. Lower surface white to brown with crystals. Apothecia common, appressed to sessile, 0.3–1.0 mm in diameter. Thalline margin yellow, concolor with the thallus, containing algae. Proper margin inapparent. Disc brown-orange to dark brown, flat to convex. Hymenium hyaline, 57.5–65.0 µm high. Epithecium yellow-brown, with numerous amorphous particles dissolving in K+ purplish red, 12.5–25.0 µm high. Paraphyses unbranched. Subhymenium and hypothecium colorless, I-, 50.0–90.0 µm, with a continuous algal layer present below the hypothecium, 87.5–200.0 µm thick. Asci clavate, 50.0–62.5 µm, 8-spored. Ascospores one-septate, some septa incomplete, ellipsoid or broader ellipsoid, sometimes slightly curved, 11.0–15.0 × 4.0–5.0 µm. Pycnidia immersed, one-chambered, rare, with an obvious orange ostiole showing at the surface, 62.5–150µm high × 37.5–115.5 µm wide. Conidia bacilliform, straight, hyaline, 4–5 µm. Chemistry: Spot test: cortex K+ purplish red, C–, medulla K–, C–. parietin and an unknown depsidone with a pink color after acid and heating as major substances detected by TLC. The Rf value of the unknown depsidone is between parietin and emodin (FIGURE 4). Etymology: The epithet farinosa refers to the upper surface of the thallus farinose with a thin and powdery crystal layer. Distribution and Ecology: Gyalolechia farinosa was mainly collected from the desert steppe belt and shallow mountain shrub belt of Helan Mountain, growing on soil or moss at an altitude of 1342–2189 m. It often grows together with Xanthoria elegans, Toninia tristis, and Buellia elegans. Notes: In the phylogram, Gyalolechia farinosa is sister to G. aurea. The latter has a continuous thallus with distinct marginal lobes, a rather well-developed cortical layer, and fusiform polarilocular spores with prolonged ends. However, G. farinosa has no distinct marginal lobes, an upper layer full of crystals, and ascospores one-septate, ellipsoid or broader ellipsoid, which readily distinguish it from other Gyalolechia species. Additional specimens examined: China, Ningxia, Helanshan National Natural Reserve, Suyukou, on soil, 1365.9 m alt. 38°43’9.0” N, 106°0’24.1” E, 28 Aug 2014, D. L. Niu 14-03-0179; Xiangshuigou, on soil, 2189 m alt. 38°46’30.9” N, 105°54’48.8” E, 10 Jun 2017, D. L. Niu 17-0448. Neimenggu, Helanshan National Natural Reserve, North Temple, on soil, 1734 m alt. 38°58’49.5” N, 105°52’12.3”E, 23 May 2023, D. L. Niu 23052329.