Pseudodactylaria guttulate J. Ma & Y.Z. Lu, sp. nov.

Index Fungorum number: IF901521; Mycobank number: MB901521; Facesoffungi number: FoF 14265 Fig. 1

Etymology – “guttulate” referring to the guttulate conidia.

Holotype – GZAAS 22-2037.

Saprobic on decaying wood. Sexual morph: Not observed. Asexual morph: hyphomycetous. Colonies on the substratum superficial, effuse, gregarious, white. Mycelium composed of partly immersed, hyaline, septate, branched hyphae. Conidiophores 45–110 × 3–4 μm (x̅=82 × 3.5 μm, n=20), macronematous, mononematous, solitary, erect, occasionally branched, subcylindrical, straight to slightly flexuous, hyaline, 1–3-septate. Conidiogenous cells 20–30 × 3–3.5 μm (x= 24 × 3.2 μm, n = 20), holoblastic, polyblastic, integrated, terminal, sympodial, subcylindrical, straight or flexuous, hyaline, apical part forming a rachis with numerous, aggregated, cylindrical denticles, 1.0–1.2 × 0.6–1.0 μm. Conidia 14–20 × 3–3.5 μm (x=18 × 3 μm, n=30).solitary, acropleurogenous, smooth, prominently guttulate, 0–1-septate, fusiform, hyaline.

Culture characteristics – Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 23 mm in 40 days at 25 °C, greyish white.

Material examined – China, Guizhou Province, Guiyang City, Changpoling National Forest Park, on decaying  wood in a terrestrial habitat, 20 August 2022, Yong-Zhong Lu, JW3.1 (GZAAS 22–2037, holotype), ex-type, GZCC 22–2037.

GenBank numbers – LSU: OR807743, ITS: OR807742

Notes – Pseudodactylaria guttulate shares a sister relationship to P. camporesiana with strong support (98% ML/ 98% MP/ 1.00 PP). However, P. guttulate differs from P. camporesiana in having longer conidiophores (45–110×3–4 μm vs. 35–45 ×3.5–5 μm) (Hyde et al. 2020a, b, c). Particularly, P. guttulate is distinguished from P. camporesiana by distinctly branched conidiophores (Hyde et al. 2020a, b, c). Based on a pairwise comparison of ITS nucleotides, P. guttulate differs from P. camporesiana by 26/693 bp (3.8%). Following the guidelines for defining species boundaries of Chethana et al. (2021a, b), we therefore introduce GZCC 22–2037 as a new species.

Figure 1 – Pseudodactylaria guttulate (GZAAS 22-2037, holotype). a, b Colonies on decaying wood; c, d Conidiophores and conidiogenous cells; e–f Conidiogenous cells with attached conidia; g–i Conidiogenous cells; j Germinated conidia; k–n Conidia; o, p Colony on PDA from above and below. Scale bars: c–d=20 μm; e–j=10 μm; k–n=5 μm