Yuxiensis granularis Bundhun, Wanas. & K.D. Hyde, sp. nov.

MycoBank number: MB 558676; Index Fungorum number: IF 558676; Facesoffungi number: FoF 10185, Figure 3.

Etymology—The specific epithet refers to the granular contents of the ascospores.

Holotype–HKAS 109580

Saprobic on dead twigs of deciduous hosts in terrestrial habitats. Sexual morph: Ascomata 250–400 µm high, 550–700 µm diam. (x = 309 × 642 µm, n = 5), astromatic to stromatic, immersed to erumpent, appearing superficial after substrate has worn away, aggregated, black, non-ostiolate, semi-globose when fresh, collapsing upon drying, without hair or bristles, with inconspicuous subiculum, coriaceous. Ascomatal wall made up of 2–3 layers, almost equally thickened, 40–70 µm wide at the apex and base, 50–70 µm wide at the sides; heavily pigmented at outermost layer, composed of thick-walled, very dark brown cells, with inner layer comprising thick-walled cells (25–45 µm) of textura globulosa to textura angularis, innermost layer composed of flattened, thin-walled cells of textura prismatica toward the locule; Munk pores visible, few per cell. Hamathecium made up of subcylindrical quellkörper, 290 µm long and 220 µm wide. Asci 40–80  ×   5–10 µm (x = 55.8 × 8.4 µm, n = 10), spore bearing part 15–30 µm, pedicel 15–50 µm, 8-spored, unitunicate, clavate, long-pedicellate, rounded at apex, lacking an apical ring, thin-walled, evanescent. Ascospores 8–15     2–3 µm (x = 11.7  ×   2.3 µm, n = 35), irregularly arranged, cylindrical to allantoid, hyaline, unicellular, aseptate, with granular contents, lacking mucilaginous sheath or appendage. Asexual morph: Undetermined.

Material examined: CHINA, Yunnan, Yuxi, Yi and Dai Autonomous County, Yuanjiang Hani, 23.74074 N, 102.17735 E, on woody litter of an undetermined deciduous host, 24 May 2019, 1345 msl, D.N. Wanasinghe, DW0636-19 (HKAS 109580, holotype).

Notes: In the multi-gene phylogeny, Yuxiensis granularis is more closely related to Pseudocatenomycopsis rothmanniae, followed by Euacanthe usambarensis (=Euacanthe foveolata [12]) (Figure 1). The LSU sequence of Yuxiensis granularis is 95% similar to Pseudocatenomycopsis rothmanniae (GenBank KF777237; similarity = 869/910(95%), Gaps = 3/910(0%)). The ITS sequence of Yuxiensis granularis is 85% similar to Pseudocatenomycopsis rothmanniae (GenBank KF777185; similarity = 470/552(85%), Gaps = 10/552(1%)). Pseudocatenomycopsis rothmanniae has only LSU and ITS sequence data deposited in GenBank, and hence the protein-coding genes, tef1 and rpb2 could not be compared. Morphological comparison between the two taxa is currently unfeasible since the single species of Pseudocatenomycopsis, P. rothmanniae, has been introduced in its asexual morph [11], while the asexual morph for Yuxiensis granularis could not be obtained.

Figure 1. Cont.

Figure 1. Phylogram generated from maximum likelihood (RAxML) based on LSU–ITS–tef1rpb2 matrix for Coronophorales. The tree is rooted with Emericellopsis alkalina (CBS 127350), Pseudohyaloseta pandanicola (MFLUCC 16-0316) and Stachybotrys microspora (KLM 3-2). Maximum likelihood bootstrap (65) and BYPP (0.95) supports are shown, respectively, above or below the branches. Type strains are in bold while novelty and the recombined taxon are in blue.

Figure 3. Yuxiensis granularis (HKAS 109580, holotype). (a) Appearance of ascomata on twig. (b) Close-up of ascomata. (c) Collabent ascoma. (d,e) Longitudinal sections of ascoma. (f) Peridium. (g) Quellkörper. (h) Munk pores (arrows). (ik) Asci. (lp) Ascospores. Scale bars: (d,e) = 200 µm, (f) = 30 µm, (g) = 100 µm, (ik) = 10 µm, (lp) = 5 µm.