Myriospora kunyuensis J.X. Wang & L. Hu, 2025

Wang, Jia-Xin, Liang, Fu-Hui, Zhou, Shu-Nuo & Hu, Ling, 2025, Myriospora kunyuensis (Acarosporaceae, lichenized Ascomycota), a new species from the eastern coast of China, Phytotaxa 708 (1), pp. 68-76 : 71-73

Myriospora kunyuensis J.X. Wang & L. Hu , sp. nov. Fungal Names : FN 571741, Mycobank No: MB858756 ( Fig. 2 )

Type:— CHINA, Shandong Province: Weihai City, Wendeng District, Kunyu Mountain Nature Reserve, Taiboding, along the downhill path, 37°14'58.24″N, 121°46'9.68″E, 888 m elev., on rock, 22 November 2024, R. T. Li, W.X. Sun & J.X. Wang 20242348 ( SDNU, Holotype) ( Fig. 2 )

Diagnosis: Similar to M. smaragdula , but differing in having smaller apothecial disc and asci, and in producing stictic acid.

Description: — Thallus epilithic, areolate or subsquamulose, up to 2.5 mm wide, rounded to very irregular, dispersed to contiguous, replicating by division, margins thin, sometimes raised from the substratum. Upper surface greyish brown or greenish brown to dull brown, rarely black, often paler towards the margin, sometimes darkening around the apothecia, epruinose, usually convex, dull to somewhat shiny. Epicortex absent or 5–25(–40) μm thick. Cortex thin, ca. 5–25 μm thick, rarely only one to two cells thick, upper layer reddish-brown, lower layer lacking or less than 10 μm thick around the apothecia. Algal layer 25–140 μm thick, becoming thin at the margin, sometimes interrupted by narrow hyphal bundles, continuous beneath apothecia, algal cells ca. 10 μm wide. Medulla ca. 25–75 μm thick, indistinct.

Apothecia 1–3(–6) per areole or squamule, immersed; disc rounded, up to 40 μm wide, brown to black, sunken or level with the thallus, rough, uneven, rarely with very small crack, epruinose. Parathecium indistinct to ca. 20 μm wide, sometimes merging with cortex, expanded up to 75 μm wide around the disc, rarely forming elevated margin concolorous with the thallus. Hymenium (100–)140–200 μm high, epihymenium 10–25 μm thick, yellowish brown to brown, paraphyses 1–2 μm wide, with expanded apices to 3 μm wide, hymenial gel IKI+ blue to red, hemiamyloid. Asci polyspored, with more of 100 ascospores, 100–140 × 20–30 μm. Ascospores simple, hyaline, ellipsoid to narrowly ellipsoid, (3–) 3.9 ± 0.54 (–6) × (1.5–) 1.75 ± 0.0875 (2.5) μm (n=20), l/b 2.3. Subhymenium 30–50(–70) μm thick, IKI+ blue, euamyloid, with oil drops. Hypothecium ca. 30 μm thick, IKI–. Pycnidia not observed.

Chemistry: —Cortex K+ yellow, PD+ orange, C–; stictic acid detected by TLC.

Etymology: —The specific epithet kunyuensis refers to Kunyu Mountain, where this species was found.

Ecology and distribution: —Currently known only from Kunyu Mountain Nature Reserve, located in eastern Shandong Province, China. This species was found on rock. Most specimens of Myriospora kunyuensis were found in the sheltered areas beneath large rocks at the mountaintop, where strong winds are prevalent.

Notes: — Myriospora kunyuensis is similar to M. tangerina (M. Westb. & Wedin) K. Knudsen & Arcadia (2012: 23) and M. westbergii by its areolate or subsquamulose thallus and greyish brown or greenish brown to dull brown upper surface. But M. tangerine differs from the new species by its taller cortex (60–95 μm vs. 5–25 μm), larger apothecial disc ((0.07–)0.10–0.25(–0.40) mm vs. 0.04 mm), and no secondary metabolites. Myriospora westbergii differs from the new species by thinner hymenium (ca. 125–150 μm vs. 140–200 μm), smaller asci (ca. 30 × 8 μm vs. 100–140 × 20–30 μm), and no secondary metabolites.

Like most Myriospora species, this new taxon also exhibits a pronounced maritime ecology, typically occurring in coastal habitats or shoreline environments. Due to the frequent strong winds at high elevation, specimens of M. kunyuensis collected from these regions usually have a thicker epicortex compared to specimnes from lower elevations (epicortex 10–25(–40) at high elev. vs. absent or 5–10 at lower elev.).

Myriospora kunyuensis is recognized by the presence of stictic acid, which is easily confirmed by a spot test (K+ yellow and PD+ orange). However, two pale green specimens of this species, exhibited a K+ yellow and PD+ orange reaction in cortex, but no secondary metabolites were detected by TLC. This phenomenon has been documented once before in Myriospora , where copper complexes with norstictic acid prevented the detection of norstictic acid by TLC in some specimens of M. smaragdula , despite their K+ red reaction ( Purvis et al. 1985). Given that both norstictic acid and stictic acid are depsidone-type lichen metabolites, we suppose that a similar copper-mediated complex may form with stictic acid, potentially explaining its apparent absence in TLC analyses. This hypothesis requires verification through targeted experimental validation to confirm.

Additional specimens examined: — CHINA, Shandong Province: Weihai City, Wendeng District, Kunyu Mountain Nature Reserve , Taiboding , along the uphill steps, 37°14'51.21″N, 121°46'14.65″E, 928 m elev., on rock, 22 November 2024, R. T. Li, W.X. Sun & J.X. Wang 20242268, 20242271, 20242274, 20242277, 20242281, 20242285 ( SDNU) ; Weihai City, Wendeng District, Kunyu Mountain Nature Reserve , Taiboding , 37°14'50.42″N, 121°46'13.78″E, 933 m elev., on rock at the peak, 22 November 2024, R. T. Li, W.X. Sun & J.X. Wang 20212288, 20242289, 20242290, 20242302, 20242304, 20242308, 20242309 ( SDNU) ; Weihai City, Wendeng District, Kunyu Mountain Nature Reserve , Taiboding , along the downhill path, 37°14'58.24″N, 121°46'9.68″E, 888 m elev., on rock, 22 November 2024, R. T. Li, W.X. Sun & J.X. Wang 20242315, 20242320, 20242322, 20242324, 20242327, 20242329, 20242334, 20242336, 20242338, 20242341, 20242347, 20242357 ( SDNU) ; Yantai City, Muping District, Kunyu Mountain Nature Reserve , Taiboding , the end of the downhill path, 37°15'20.90″N, 121°45'18.07″E, 560 m elev., on rock, 22 November 2024, R. T. Li, W.X. Sun & J.X. Wang 20242423 ( SDNU) ; Yantai City, Muping District, Kunyu Mountain Nature Reserve , Six Branch of Forestry Station, Longxu Bridge , 37°17'32.59″N, 121°41'35.30″E, 154 m elev., on rock, 22 November 2024, L.L. Zhang, Z.H. Yang & X. Wang 20242087 ( SDNU) ; Yantai City, Muping District, Kunyu Mountain Nature Reserve , Five Branch of Forestry Station , near The Yuelao Temple , 37°17'46.06″N, 121°45'17.82″E, 124m elev., on rock, 23 November 2024, L.L. Zhang & R. T. Li 20242237 ( SDNU) ; Yantai City, Muping District, Kunyu Mountain Nature Reserve , Five Branch of Forestry Station, Yuegudian , 37°18'0.03″N, 121°44'32.80″E, 169m elev., on rock, 23 November 2024, L.L. Zhang & R. T. Li 20242217 ( SDNU) .

Figures

FIGURE 2. Myriospora kunyuensis sp. nov. (A, C-H: holotype, SDNU 20242348; B: SDNU 20242290).A, B. Thallus with apotheica. C. Vertical section of apothecium. D. Vertical section of apothecium under polarized light showing location of crystals. E. Vertical section of cortex. F. Hemiamyloid reaction of hymenium with Acarospora-type ascus. G, H. Ascospores. Scale bars: A, B = 1mm, C-E = 40 µm, F = 20 µm, G, H = 5 µm.