Dicephalospora maetaengica L. Luo & K. D. Hyde 2025, sp. nov.

Dicephalospora maetaengica L. Luo & K. D. Hyde sp. nov. Fig. 3 Etymology. The epithet “ maetaengica ” refers to the collection site, MaeTaeng District, where the holotype specimen was collected. Holotype. MFLU 24-0330. Description. Saprobic on dead leaves. Sexual morph: Apothecia 1.5–3.3 mm diam., when dry arising solitary, uniseriate on the stem of the leaves, centrally long stipitate, superficial, yellow when fresh and dry. Stipe 1.2–2.5 mm height, slightly hyaline to light yellow at the base. Receptacle yellow and cupulate. Margins smooth, yellow to pale yellow. Disc slightly sunken and yellow. Ectal excipulum 23–44 µm (x ̄ = 33 µm, n = 60), multi-layered, thin-walled, hyaline to light yellow or pale green cells of textura globulosa, slightly larger cells condensed. Medullary excipulum 28–61 µm (x ̄ = 45 µm, n = 60), composed of thin-walled, hyaline to yellowish, gelatinized cells of textura porrecta to globulosa, small cells condensed. Hymenium 99–146 µm (x ̄ = 123 µm, n = 60), hyaline to yellow, inner mixed with asci and paraphyses. Paraphyses 1.1–2.1 µm wide (x ̄ = 1.6 µm, n = 60), filiform, numerous, lengths exceeding the asci, unbranched, aseptate, slightly swollen, small, globose at the apex. Asci (75 –) 81–111 (– 118) × 5.6–10.7 µm (x ̄ = 99 × 8.5 µm, n = 50), eight-spored, unitunicate, cylindrical, clavate, amyloid (J +) having a rounded apex in Melzer’s reagent, tapered long stipitate base. Ascospores (12.5 –) 14.5–21.8 (– 22.5) × 2.4–4.2 µm (x ̄ = 18.2 × 3.3 µm, n = 60), uniseriate to biseriate, fusiform, guttulate, 0–1 – septate. Asexual morph: Not observed. Material examined. Thailand • Chiang Mai Province, MaeTaeng District, Pha Deng Village, Mushroom Research Center (MRC), altitude 863 m, on the decayed unidentified leaf, 18 August 2023, Le Luo, RB 1 (MFLU 24-0330, holotype); • ibid., RB 101 (MFLU 24-0331, paratype). Notes. Dicephalospora maetaengica formed a clade closer to D. menghaica with 100 % MLBS and 1.00 BIPP support (Fig. 1). These two species grouped as a sister clade and together formed a closely related clade to D. albolutea with 98 % MLBS and 1.00 BIPP (Fig. 1) bootstrap support. Dicephalospora maetaengica differs from D. menghaica by having larger (1.5–3.3 mm vs. 1–1.6 mm), yellow apothecia, long stipe (1.2–2.5 mm vs. 0.6–1 mm), slightly hyaline to light yellow at the base of stipe, 0–1 – septate ascospores with paraphyses that are unbranched and aseptate, while D. menghaica has smaller apothecia, shorter stipe and slightly hyaline to light yellow at the base with branched paraphyses. Dicephalospora albolutea differs from D. maetaengica in having yellowish-white apothecia, longer asci (140–156 × 9.5–10.5 µm vs. 81–111 × 5.6–10.7 µm) and ascospores (26–31 × 3.8–5 µm vs. 14.5–21.8 × 2.4–4.2 µm) with aseptate paraphyses and ascospores (Zheng and Zhuang 2019). Therefore, D. maetaengica is introduced here as a new species.