Trimmatothelopsis anthracina J. X. Wang & L. Hu, 2025

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

Fig. 2 View Figure 2

Diagnosis.

Similar to Trimmatothelopsis versipellis but differing in having IKI + blue turning red hemiamyloid hymenial gel and in having the IKI + blue ascus.

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. 20242446 ( SDNU, holotype) GoogleMaps .

Etymology.

The epithet refers to the black carbonized apothecia when mature.

Description.

Thallus rare, of dispersed or contiguous irregular areoles, (0.15 –) 0.5–0.75 mm wide, sometimes indistinct, replicating by division, usually a biofilm composed of soil particles and algal cells at the immature apothecia base, ca. 30–50 μm thick, then dead when apothecia mature and easy separation from the substrate. Upper surface dull brown to black, rough, epruinose. Epicortex thin, ca. 5 μm thick. Cortex 25–40 μm thick, upper layer 10–15 μm thick, brown, lower layer hyaline. Algal layer continuous, uninterrupted, sometimes extending below apothecia, algal cells ca. 10 μm wide. Medulla obscured with crystals and gelatinization. Apothecia usually 1–3 (– 8) per areole, often with compound apothecia, 0.25–0.5 mm in diameter, brown to black, hemispherical, sometimes irregular, usually arising individually from the biofilm, initially punctiform, later dilated, sometimes arising individually from thallus, disc dull brown to black, usually carbonized, ca. 0.15 mm wide, usually circular, slightly concave or flat, sometimes with an umbo of the same color as the disc, (10 –) 12.5–15 (– 25) μm thick, rarely with slightly elevated apothecial crown. Out wall of apothecia (10 –) 12.5–15 (– 25) μm thick, carbonized, with inter thalline area sometimes absent, resulting in a space between the carbonized outer wall and the hymenium. Parathecium 40–50 μm thick, IKI-. Hymenium (200 –) 225–250 μm high, paraphyses 1.5–2 μm wide, apices expand, up to 4 μm wide, hymenial gel IKI + blue turning red, hemiamyloid, if IKI too diluted with water on the slide, the reaction is IKI- pale yellow. Asci clavate, 110–140 × 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, ascospores several hundred per asci, narrowly ellipsoid, (4 –) 5–6 (– 7) × 1.5–2 μm. Subhymenium ca. 50–75 μm thick, IKI +, blue. Hypothecium obscured, ca. 10–20 μm thick, IKI-. Pycnidia not observed. Not producing secondary metabolites.

Habitat and distribution.

This new species is so far only known from Kunyu Mountain Nature Reserve, Shandong Province. It occurs on non-calcareous rock from the south-facing slopes located in the valley, at an elevation of 304 m.

Notes.

Trimmatothelopsis anthracina is similar to T. americana , T. coreana , and T. versipellis by its carbonized apothecial margin. Trimmatothelopsis americana differs in its uncarbonized apothecial disc and small ascospores (3–5 × 0.5–1 μm) ( Knudsen and Lendemer 2016). Trimmatothelopsis coreana differs in its apothecia immersed in the thalline warts, no biofilm, uncarbonized apothecia disc, lower hymenium (up to 190 μm high), and lower subhymenium (up to 40 μm thick) ( Kondratyuk et al. 2015). Trimmatothelopsis versipellis differs in its IKI + blue euamyloid hymenial gel and IKI- ascus ( Gueidan et al. 2014).

Before this study, T. versipellis was reported from Kunyu Mountain Nature Reserve where we found T. anthracina and T. shandongensis . However, the morphological re-examination of the sole specimen (Ren 5389 SDNU) revealed significant discrepancies from the original description by Xiong et al. (2020). In Xiong’s description, this species has red-brown thallus, low hymenium (100–130 μm high), and IKI + blue hymenial gel. However, during our re-examination of this specimen, it actually has brownish to dull brown thallus, globose apothecia, hymenium ca. 200 μm high, IKI + blue turning red hymenial gel, IKI + blue ascus, and ascospores 4.5–6.25 × 2.5–3 μm. Unfortunately, we could not sequence this specimen. Based on these characteristics, this specimen should not belong to T. versipellis which had carbon black thallus, IKI + blue hymenial gel, IKI- ascus, and small ascospores 3–5 × 1–2 μm ( Gueidan et al. 2014). However, this specimen shares many morphological and chemical characteristics with T. anthracina : dull brown thallus, high hymenium (ca. 200 μm), IKI + blue turning red hymenial gel, and IKI + blue ascus. Furthermore, both of them were collected along the Sancha River in the Kunyu Mountain Nature Reserve. In summary, we identified this specimen as T. anthracina .

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. 20242211, 20242212, 20242224, 20242244, 20242447 ( SDNU) GoogleMaps .