Coniocarpon chishuiense Lin-Zhi He & Shao-Bin Fu sp. nov.

Fig. 4

Etymology.

The specific epithet chishuiense refers to the location (Chishui City) where the holotype was collected.

Holotype.

KUN-L 97467

GenBank.

PV 990242 (ITS, KUN-L 97467); PV 990243 (mtSSU, KUN-L 97467)

Description.

Sexual morph: Thallus crustose, thin, olive, rough, dull, with obvious edge. Apothecia irregularly rounded to elliptical, numerous, convex, sessile, with steeply dipping, emergent from thallus, 0.3–0.5 mm × 0.2–0.3 mm, solitary or forming loose to dense. Disc sepia, epruinose, flat to weakly convex. Exciple brown, uncarbonized. Epihymenium brown, 28–39 μm tall, I + blue, K –. Hymenium is hyaline to reddish brown, not inspersed, 104–165 μm tall, I + blue then turning red, K –. Hypothecium brown, 31–48 μm tall, I + blue, K –. Paraphyses simple, unbranched, with colorless apices. Asci 8 - spored, hyaline, long obpyriform to clavate, (46.0 –) 54.0–70.0 (– 74.0) × (23.5 –) 23.5–27.5 (– 30.0) μm, I –, K –. Ascospores obovate, (2 –) 3–5 (– 5) - septate, showing purple (in water) and hyaline (in KOH), (20.5 –) 21.5–26.5 (– 29.0) × (6.5 –) 7.5–9.0 (– 9.5) μm (x ̄ = 24 × 8 μm, n = 20), I –, K –. Asexual morph: not observed.

Chemistry.

Thallus K + blackish purple, C –, KC + purple, P –, UV –. TLC: psoromic acid and an unknown lichen substance.

Material examined.

China • Guizhou Province, Chishui City, Chishui National Nature Reserve, 28°21'49"N, 105°59'51"E, 1125 m elev., on bark, 12 July 2024, ShaoBin Fu, WeiWei Zheng, Coll. No. CS 78 (holotype, KUN-L 97467).

Notes.

The phylogenetic analysis of mtSSU sequence data reveals that Coniocarpon chishuiense is closely related to C. cinnabarinum, C. cuspidans in and C. fallax. The nucleotide comparison differences between C. chishuiense and C. cinnabarinum, showed differences of 1.47 % (11 / 747 bp) for mtSSU. Morphologically, the new species differs by epruinose disc (vs. reddish or white pruina in C. cinnabarinum). In addition, the asexual moprh (pycnidia and conidia) is absent in new species but present in C. cinnabarinum. Chemically, C. chishuiense contains both psoromic acid and an unidentified lichen substance, while C. cinnabarinum contains only psoromic acid (Nash et al. 2004; Frisch et al. 2020).

There were 2.00 % differences (15 / 747 bp) in sequences of mtSSU between Coniocarpon chishuiense and C. cuspidans in. Additional differences include the larger ascospores in the new species (21.5–26.5 × 7.5–9.0 μm vs. 16–18 × 7–8 µm in C. cuspidans) and the presence of psoromic acid and an unknown lichen substance in C. chishuiense but not in C. cuspidans (Frisch et al. 2020). C. chishuiense can be distinguished from C. fallax by its epruinose disc (vs. orange-red pruina in C. fallax) and larger ascospores (21.5–26.5 µm vs. 17–20 μm). Furthermore, C. chishuiense contains psoromic acid and an unknown lichen substance, both absent in C. fallax. Nucleotide comparison is also considerable, with differences of 3.61 % (27 / 747 bp) in mtSSU (Frisch et al. 2020).

In addition to the above three species, the new species, Coniocarpon chishuiense, shares similar morphology with Coniocarpon carneoumbrinum (Zahlbruckner) Van den Broeck & Ertz, Coniocarpon rubrocinctum (G. Merr. ex Grube & Lendemer) Perlmutter, R. Miranda & Bungartz and Coniocarpon tuckermanianum (Willey) Van den Broeck & Ertz in size of ascospores (Table 4). However, all three of these species have a pruinose disc, whereas our species lacks pruina. A distinct contrast is observed in thallus coloration among the three species C. carneoumbrinum, C. tuckermanianum and C. chishuiense: gray vs. white vs. olive. Besides, Coniocarpon rubrocinctum contain only psoromic acid, while C. chishuiense contains an unknown lichen substance except for psoromic acid. Based on the descriptions of thallus and apothecial color, the new species is distinct from all known species.