Pseudorhypophila formosana K. W. Cheng & H. A. Ariyaw. 2025, sp. nov.

Pseudorhypophila formosana K. W. Cheng & H. A. Ariyaw. sp. nov. Fig. 34 Typification. TAIWAN • Guanshan Township, Taitung County, 23°02'14.8"N, 121°11'22.6"E, serpentine soil in rice field, 3 rd November 2022, K. W. Cheng, holotype, NTUPPMH 22-226 (Permanently preserved in a metabolically inactive state), ex-holotype NTUPPMCC 22-297, ex-isotype NTUPPMCC 22-295, 296, 298 to 300. Etymology. Named after Formosa, the former name of Taiwan, where the type specimen was collected. Description. Sexual morph Ascomata 342–504 µm diam, non-ostiolate, globose, dirty gray when immature, black when mature, submerged in PDA. Peridium multi-layered, brown, translucent, membranous, angular cells. Asci clavate to cylindrical, hyaline when immature, eight-spored, 74–111 µm × 14–21 µm (x ̄ = 90.9 × 17.8 µm, L / W ratio = 5.13, n = 20). Ascospores two-celled; upper cell ellipsoidal to slightly fusiform, smooth, brown, multiple guttules, subapical germ pore, 18.3–24.6 µm × 8.8–12.5 µm (x ̄ = 21.3 × 11.0 µm, L / W ratio = 1.95, n = 50), lower cell cylindrical with slightly tapering or rounded end, hyaline to pale brown, thin-walled, 4.0–8.0 µm × 3.1–5.8 µm (x ̄ = 5.8 × 4.3 µm, L / W ratio = 1.36, n = 50). Asexual morph undetermined. Culture characteristics. Colony exhibit rapid growth, reaching 80 mm diam with flat, sparse aerial mycelium, white, surface and margins slight smooth. The reverse exhibited blackish-gray center, with a gradient radiating outward into lighter gray tones. Notes. In the present study, six Pseudorhypophila strains (NTUPPMCC 22-295 to 300) formed a distinct clade with a strong statistical support (100 % / 1.00), clearly separating from known Pseudorhypophila species in the multi-locus phylogenetic analysis (Fig. 35). Furthermore, the ex-type strain of Pseudorhypophila formosana (NTUPPMCC 22-297) exhibits significant genetic divergence from its closest relatives, the ex-type strains of P. mangenotii (CBS 419.67) and P. poae (CMML 20-36), with 94.0 % (936 / 996 bp) and 94.2 % (938 / 996 bp) identity, respectively, in the rpb 2 gene. In line with earlier research on P. marina and P. pilifera, our isolate produces ascomata lacking ostioles and bearing 2 - celled ascospores, a distinctive trait of the Pseudorhypophila (Harms et al. 2021). However, P. formosana NTUPPMCC 22-297 is distinguished by its lower cell lengths, which are noticeably smaller than those of the type species, P. marina CBS 698.96 (4–8 µm × 3–6 µm versus 6–13 µm × 3–5 µm) (Fig. 34; Guarro et al. 1997). Moreover, P. poae has been recorded only in its asexual morph, which was not observed in our strains (NTUPPMCC 22-295 to 300). Notably, the other representative strain of P. marina (Zopfiella marina CBS 155.77) was previously reported from Taiwan. However, it also differs from P. formosana NTUPPMCC 22-297 in morphology, phylogeny and habitat (marine mud versus terrestrial serpentine soil) (Overy et al. 2014; Harms et al. 2021).