Torrentispora fibrosa Hyde et al.
Etymology: from the Latin fibrosa meaning fibrillar, in relation to the appearance of the ascospore sheath.
Sexual morph: Ascomata 135–255 µm diam, globose to subglobose, immersed or superficial, black, coriaceous, papillate, ostiolate, solitary. Neck long, black, periphysate. Peridium to 21.5 µm wide, in vertical section composed of an outer layer of dark-brown, angular cells, heavily pigmented and amorphous at the periphery, and an inner layer of hyaline, compressed cells; in surface view comprising black, thick-walled cylindrical cells, arranged in irregular rows. Paraphyses to 5.5 µm wide, filamentous, numerous, septate, slightly constricted at the septa, and tapering distally. Asci 154–254 ´ 6–9 µm (x̄ = 184 ´ 8 µm, n = 25), 8-spored, long cylindrical, pedicellate, thin-walled, with a relatively massive refractive apical ring, ca 2.5 µm long and 4.5 µm wide. Ascospores 13.5–19.5 ´ 5–7 µm (x̄ = 17 ´ 6 µm, n = 50), uni-seriate, oval to fusiform, occasionally flattened on one side, hyaline, unicellular, thick-walled, surrounded by a narrow fibrillar sheath (visible in India Ink and with the SEM). Asexual morph: Undetermined. (Hyde et al. 2000)
Distribution: CHINA, Hong Kong, New Territories, Tai Po, Lam Tsuen River and Tai Po Kau Forest Reserve, Tai Po Kau Forest Stream, on submerged decaying wood (Hyde et al. 2000); NEW ZEALAND, Lake Christabel track, on decaying wood of Nothofagus sp. (Réblová et al. 2018).
Notes: Holotype HKU (M) 4519 (now in IFRD), other specimen collected from freshwater habitats PDD 110879. LSU, SSU and RPB2 sequence data are available.
Hyde KD, Ho WH, Jones EBG, Tsui CKM, Wong WSW (2000) Torrentispora fibrosa gen. sp. nov. (Annulatascaceae) from freshwater habitats. Mycol Res 104:1399–1403
Luo ZL, Hyde KD, Liu JK, Maharachchikumbura SSN et al. 2019 – Freshwater Sordariomycetes. Fungal Diversity 99, 451–660.
Réblová M, Miller A, Reblová K, Štepánek V. 2018 – Phylogenetic classification and generic delineation of Calyptosphaeria gen. nov., Lentomitella, Spadicoides and Torrentispora (Sordariomycetes). Studies in Mycology 89, 1‒62.
Figs. 1–14. Torrentispora fibrosa. Interference contrast micrographs. 1. Immersed ascoma with a long, black neck. 2. Superficial ascoma. 3. Section of peridium comprising an outer layer of black, thick-walled, angular cells, and an inner hyaline compressed cell. 4. Surface view of peridium. Note the arrangement of the black, thick-walled, cylindrical cells. 5. Wide, hyaline and septate paraphyses and young asci. Figs 6–8. Long cylindrical asci with uniseriate ascospores. Note the relatively massive refractive apical rings. 9–10. Higher magnification of apical rings. 11–14. Hyaline and non-septate ascospores. Note that the sheath is indistinct, except when India Ink is added (Figs. 12–13). Scale bars 1–2 = 100 µm, 3–8, 11–14 = 10 µm, 9–10 = 5 µm.