Coccomyces fanjingshanensis T. Lv & W. Zang, 2020

Zang, Wei, Lv, Tu, Sun, Jianqiu & Hou, Chenglin, 2020, A new species of Coccomyces from Guizhou Province of China, Phytotaxa 446 (1), pp. 23-32 : 27

Coccomyces fanjingshanensis T. Lv & W. Zang sp. nov. ( Figs. 3 ) MycoBank: 833856

Diagnosis: The new taxon differs from Coccomyces Cyclobalanopsis Y.R. Lin & Z.Z. Li ,which produce ascomata on leaves of Cyclobalanopsis sp. , by having subepidermal to intraepidermal, triangular to pentagonal ascomata, internal matrix of stroma and periphysoid absent, wider asci (6–8 vs 4–5) ( Lin et al., 2000).

Holotype: CHINA, Guizhou Province, Tongren, Fanjingshan National Nature Reserve, alt. ca 969 m, on dead leaves of Cyclobalanopsis sp. ( Fagaceae ), 18 August 2019, C.-L. Hou 1493 (BJTC 202043, holotype).

Etymology: fanjingshanensis , referring to the name of Fanjingshan where the specimens were collected.

Ascomata developing on both sides of dead leaves, scattered or occasionally coalescent, slightly raising above the surface, subepidermal to intraepidermal, triangular to pentagonal, brown to slightly black, 400–750 μm diam. (= 612 μm), with a preformed dehiscence mechanism, opening by 3–5 radial splits which extend nearly to the edge of ascoma to expose the hymenium. Stroma 18–50 μm thick near the center of ascomata, consisting of 3–9 μm carbonized thick-walled angular to global fungal cells. Periphysoids and lips absent. Basal stroma 15–35 μm, consisting of 4–8 μm thick-walled angular and global cells. Spaces triangular in section in the edges of the ascomata filled with thin-walled angular cells. Subhymenium hyaline, 15–40 μm thick, consisting of textura intricate. Excipulum formed by marginal paraphyses, excipular elements similar to paraphyses. Paraphyses filiform, 70–150 × 1 μm (= 108.5 × 1 μm), gradually enlarged to 2–4 μm and fusoid at the apex, covered by a very thin gelatinous sheath, forming a thin epithecium. Asciripening sequentially, 60–125 × 6–8 μm (= 94.2 × 6.7 μm), cylindrical, short-stalked, thin-walled, 8-spored. Ascospores arranged fasciculately, 20–57 × 1–2 μm (= 37.2 × 1.6 μm), filiform, hyaline, aseptate, with fewguttules, covered by a thin gelatinous sheaths. Conidiomata not seen. Zone lines brown to black, 30–70 μm wide.

Known distribution: Known only from Guizhou Province, China.

Additional specimens examined: CHINA, Guizhou Province,Tongren, Fanjingshan National Nature Reserve, alt.ca 1140 m, on dead leaves of Cyclobalanopsis sp. ( Fagaceae ), 18 August 2019, C.-L. Hou 1495 (BJTC 202044); CHINA, Guizhou Province, Tongren, Fanjingshan National Nature Reserve, alt. ca 968 m, on dead leaves of Cyclobalanopsis sp. ( Fagaceae ), 18 August 2019, C.-L. Hou 1490A (BJTC 202039). CHINA, Guizhou Province, Tongren, Fanjingshan National Nature Reserve, alt. ca 1197 m, on dead leaves of Quercus sp. ( Fagaceae ), 18 August 2019, C.-L.Hou 1500A (BJTC 202045).

Figures

FIGURE 3. Coccomyces fanjingshanensis (Holotype, BJTC 202043) on Cyclobalanopsis sp.: A and B. Mature ascoma observed under a dissecting microscope.C.Ascoma in median vertical section; D. Paraphyses, mature asci with ascospores, and empty ascus after ascospores discharged; E. Discharged ascospores.