Trimmatothelopsis shandongensis J. X. Wang & L. Hu sp. nov.

Fig. 4

Diagnosis.

Similar to Trimmatothelopsis mexicana but differing in having dull brown thallus and apothecia, in having smaller apothecial disc (0.1 mm vs. 1–2 mm), and in having lower hymenium (120–140 μm vs. 200–220 μm).

Type.

China • Shandong Province: Yantai City, Muping District, Kunyu Mountain Nature Reserve, the steep slope near the road, 37°15'29.44"N, 121°43'12.02"E, alt. 304 m, on non-calcareous rock, 23 Nov. 2024, J. X. Wang et al. 20242240 a (SDNU, holotype).

Etymology.

The specific epithet shandongensis refers to Shandong Province, where this species was found.

Description.

Thallus of dispersed or contiguous irregular areoles and subsquamules, 0.25–0.75 mm wide, replicating by division. Upper surface dull brown, usually with black undertone, rough, epruinose. Epicortex thin, ca. 5 μm thick. Cortex 30–50 μm thick, upper layer brown, ca. 8–12 μm thick, lower layer hyaline. Algal layer 50–75 μm thick, sometimes interrupted by hyphal bundles, algal cells mostly 8–15 μm wide. Medulla obscured with crystals and gelatinization, sometimes interspersed with a few algal cells. Apothecia rare, usually 1–2 per areole, immersed, disc up to 0.1 mm wide, concave, blackish brown, slightly darker than thallus, with slightly elevated apothecial crown, sometimes punctiform, epruinose. Parathecium indistinct, ca. 10–20 μm wide, merging with cortex, IKI-. Hymenium 120–140 μm high, paraphyses ca. 1.5 μm wide, apices unexpanded, lacking pigment caps, hymenial gel IKI + red, hemiamyloid, if IKI too diluted with water on the slide the reaction is IKI- pale yellow. Asci clavate, 95–120 × 15–25 μm, ascus stain IKI + light blue tholus and space between the outer and inner wall of the ascus before ascospores fill the asci, the blue area in upper layers of the tholus evanescent, ascospores several hundred per asci, narrowly ellipsoid, 5–7 × 2–3 μm. Subhymenium ca. 20 μm thick, hard to distinguish from hymenium, IKI-. Pycnidia immersed with dark ostioles, subglobose, 90–120 × 80–100 μm, with conidiogenous cells ca. 20 × 2 μm, conidia bacilliform, 4–6 × 1–1.5 μm. Not producing secondary metabolites.

Habitat and distribution.

This new species is only known from Kunyu Mountain Nature Reserve, Shandong Province, on non-calcareous rock at an elevation of 304 m. The holotype was collected on a steep sunny slope, growing with T. anthracina.

Notes.

Trimmatothelopsis shandongensis differs from other species in the genus Trimmatothelopsis by lower hymenium 120–140 μm high. The new species shares areolate to squamulose thallus and IKI + red hymenial gel with T. mexicana and T. oreophila, but T. mexicana differs in having a pale brown thallus with stipe, brown apothecia, and the longest conidia (up to 13.9 μm long) in this genus (Knudsen et al. 2023 a). Trimmatothelopsis oreophila differs from this new species in having apothecia with brownish red disc, IKI- ascus, and thicker subhymenium (30–50 μm vs. 20 μm) (Knudsen et al. 2021 a). The dull brown surface of thallus was also found in T. terricola, but it differs in having rhizohyphae in root-like bundles and IKI- ascus (Knudsen 2007; Knudsen and Lendemer 2016). Trimmatothelopsis shandongensis also shares some features with T. anthracina: the blackish brown areolate thallus with completely immersed apothecia and IKI + blue ascus, but T. shandongensis differs in its uncarbonized apothecia and IKI + red hymenial gel.

Additional specimens examined.

China • Shandong Province: Yantai City, Muping District, Kunyu Mountain Nature Reserve, the steep slope near the road, 37°15'29.44"N, 121°43'12.02"E, alt. 304 m, on non-calcareous rock, 23 Nov. 2024, J. X. Wang et al. 20242240 b (SDNU).