Saprobic on dead woody twigs of Castanopsisdelavayi (Fagaceae). Sexual morph: Ascomata 110–130 × 120–130 μm (x̄ = 122 × 126 μm, n = 5), solitary, scattered, erumpent to immersed, uni-loculate, globose to subglobose, black. Ostioles central. Peridium 7–12 μm wide, thin, comprising 3–4 layers of light brown to brown cells of textura prismatica. Hamathecium 1.5–2.5 μm wide, cylindrical, filiform, hyaline, septate, branched, cellular pseudoparaphyses, embedded in a gelatinous matrix. Asci 45–63 × 9–11 μm (x̄ = 55 × 9.5 μm, n = 20), 8-spored, bitunicate, fissitunicate, clavate, slightly broad at center, apically rounded, with short and rounded pedicel, minute ocular chamber. Ascospores 19–22 × 4–4.6 μm (x̄ = 20.7 × 4.2 μm, n = 30), overlapping, biseriate, hyaline, narrowly fusiform, straight or slightly curved, with 3 transverse septa, enlarged at the second cell, constricted at the septa, smooth-walled, guttulate, without a mucilaginous sheath. Asexual morph: see Magaña-Dueñas et al. (2021).

Ascospores germinated on PDA within 24 h at room temperature (25 °C). Germ tubes produced from the basal and apical cells of ascospore. Colonies on PDA, reaching 25 mm diameter after 2 weeks at 20–25 °C, mycelia superficial, medium density mycelia, entire margin, umbonate at center, band, rough surface, velvety, raised, grayish yellow, white mycelium attached to the central surface; reverse atrovirens.

China, Yunnan Province, Baoshan (25°18'48"N, 99°09'50"E), on dead woody twigs of Castanopsisdelavayi (Fagaceae), 12 July 2020, G.C. Ren, BS42 (HKAS 122713), living culture KUNCC 21-0523.

Capafonts and Castanopsisdelavayi, freshwater submerged plant debris and terrestrial, China and Spain (Magaña-Dueñas et al. 2021; this study).

Multi-loci phylogenetic analyses based on a concatenated LSU, ITS, tef1-α, rpb2, and tub2 sequence dataset show that our new collection (KUNCC 21-0523) formed a sister lineage to the ex-type strain of Paraphomaaquatica (FMR 16956) with solid support (100% ML and 1.00 BYPP, Fig. 4). Sequence comparison for the ITS region between Paraphomabaoshanenses (KUNCC 21-0523) and P.aquatica (FMR 16956) showed a 6.17% (30/486 bp) base pair difference, 0.12% (2/848 bp) base pair difference for LSU region, 2.06% (9/437 bp) base pair difference for the tef1-α region. Unfortunately, the morphology could not be compared as Paraphomaaquatica was reported in its asexual morph with no information on its sexual morph (Magaña-Dueñas et al. 2021). The species of Paraphoma were introduced from its asexual morph (Morgan-Jones and White 1983; de Gruyter et al. 2010; Quaedvlieg et al. 2013; Moslemi et al. 2016, 2018; Crous et al. 2017, 2021a, 2021b; Gomzhina et al. 2020; Magaña-Dueñas et al. 2021; Guarnaccia et al. 2022), while we introduced our new collection from its sexual morph. Therefore, we could not compare our new collection with other Paraphoma species. However, based on the phylogenetic distinctiveness, we introduce our collection as the first record of P.aquatica from Castanopsisdelavayi (Fagaceae) in China, and our species is the first sexual morph recorded in this genus.