Tatraea aseptata H.L. Su & Q. Zhao, sp. nov. Fig. 1

Index Fungorum number: IF 559987; Facesoffungi number: FoF 12892; Fig. 1

Etymology – The epithet refers to aseptate ascospores.

Saprobic on dead stems. Sexual morph: Apothecia 0.3–0.6 cm diam., up to 0.3 cm high when fresh, superficial, scattered, slightly leathery, shortly stipitate. Hymenium 150–230 µm thick, flat to slightly invaginate, surface smooth, grey to slightly reddish brown when fresh, brown when dry. Margin flat to slightly involute, light brown. Receptacle discoid to campanulate, light puce when fresh, brown when dry, rough. Hairs 40–85 × 6–8 µm (x̄ = 64 × 7 µm, n = 20), slightly needle-like with rounded apex, smooth, thick-walled, septate, hyaline, light brown. Ectal excipulum 90–290 µm thick, comprised of textura angularis cells, 5–20 × 4–13.5 µm (x̄ = 12 × 7.5 µm, n = 24), thin-walled, light yellow to light brownish. Medullary excipulum 485–725 µm thick, comprised of textura intricata cells, 3.5–7 µm (x̄ = 4.4 µm, n = 25) diam., thin-walled, slightly lighter than ectal excipulum. Paraphyses 1.5–3.5 µm (x̄ = 2.3 µm, n = 25) diam., equal to asci in length, filiform with obtuse apex, septate, unbranched, thin-walled, hyaline. Asci 150–185 (–190) × (12–) 13–18 µm (x̄ = 171 × 15 µm, n = 24), 8-spored, clavate, hyaline, rounded apex, amyloid at apex, apically thickened and laterally thin wall, with an ocular chamber. Ascospores (120/4/2) (18.5–) 21–28 (–32) × 7–9.2 (–10) µm, (x̄ = 24.2 × 8.2 µm, n = 119, Q = 2.11–4.38 µm, Qm = 2.97 ± 0.35 µm), uniseriate, reniform with tapered or rounded apices, aseptate, slightly smooth, slightly thick-walled, hyaline, uni- to multi-guttulate, mostly one oil guttule. Asexual morph: Undetermined.

Material examined – China, Yunnan, Ailao Mountains, alt. 2428 m, on the bark of a dead branch, 2 September 2021, H.L. Su, SHL206 (HKAS 124623, holotype); ibid., alt. 2328 m, on the bark of a dead branch, 28 August 2021, H.L. Su, SHL51 (HKAS 124624, paratype).

GenBank accession numbers – HKAS 124623: OP538030, HKAS 124624: OP538031.

Notes – Based on the phylogenetic tree obtained from ITS sequence analysis (Fig. 2), our specimen clustered sister to Tatraea dumbirensis with 88% maximum likelihood bootstrap and 0.67 Bayesian posterior probability support. Tatraea has two accepted species, T. macrospora and T. dumbirensis (Svrček 1992, Baral et al. 1999, Perić 2013, Van Vooren & Mourgues 2009, Wijayawardene et al. 2022). Compared to our new species, T. macrospora and T. dumbirensis have different mature ascospore morphologies (Svrček 1992, Baral et al. 1999, Perić 2013, Van Vooren & Mourgues 2009). Tatraea macrospora has 3–8-septate ascospores (Baral et al. 1999) and T. dumbirensis has 1–2-septate ascospores (Svrček 1992), while our species has aseptate ascospores (Fig. 1). Furthermore, our species has light puce receptacle, while T. macrospora and T. dumbirensis have shallow cream-colored to grayish receptacle.

Fig.1 Tatraea dumbirensis (HKAS***, holotype) a Habit. b–e Tatraea dumbirensis on substrate. f Vertical section of apothecia. g Excipulum. h Ectal excipulum. i Hair. j Paraphyses. k‒m Asci. n Asci in Melzer. o Apex of asci in Melzer. p Base of asci. q‒s Ascospores. t Ascospores in Melzer. Scale bars: f = 500μm, g = 100 μm, h‒n = 50 μm, o−t = 10 μm.

Fig. 2 – Phylogram generated from maximum likelihood analysis of Tatraea taxa based on ITS sequence data. Thirteen strains are included in the analyses, which comprised of 430 characters. Tree topology of the maximum likelihood analysis is similar to the Bayesian analysis. The best RaxML tree with a final likelihood value of -12735.79 is presented. The matrix had 112 distinct alignment patterns, with 0.14% of undetermined characters or gaps. Evolutionary model applied for ITS gene is GTR+I+G. Maximum likelihood bootstrap values equal to or greater than 80% and Bayesian posterior probabilities equal to or greater than 0.90 (MLBS/BYPP) are given at the nodes. The tree is rooted to Connersia rilstonii (CBS 537.74) and Pleuroascus nicholsonii (CBS 345.73). The ex-type strains are indicated in bold and newly generated strains are in yellow.