Rossmaniella cryptica Darmostuk, Etayo & Flakus 2025, sp. nov.

Rossmaniella cryptica Darmostuk, Etayo & Flakus, sp. nov. MycoBank MB 858386. Figs 3I, 4A, 8. Etymology: Named after morphological similarity to Rossmaniella filispora. Typus: Bolivia, Tarija Department, Aniceto Arce Province, Reserva Nacional de Flora y Fauna Tariquía, between la Cumbre and camamento los Alisos, 22º00’41”S, 64º36’02”W, 2560 m a.s.l., Boliviano-Tucumano forest with Alnus acuminata and Polylepis, on Hypotrachyna sp., 22 Jul. 2015, A. Flakus 26967 (holotype KRAM L-74683, isotype LPB). Ascomata perithecioid, ovoid to pyriform, not collapsed when dry, superficial, solitary to clustered in groups of 3–4(–7) ascomata, vivid orange, with brighter ostiole part, (330–)350–390(–450) × (220–)235–260(–280) µm (n = 10), lower half to entire ascomata covered by dense yellowishorange tomentum, composed of hyaline, septate, thin-walled, verruculose hyphae, 4–5 μm thick. Ascomatal wall 28–35 μm thick, slightly thicker at the upper part, hyaline to pale yellow, composed of two layers of cells: external layer composed of 3–5 layers of isodiametric, thin-walled cells, 5–6 μm in diam; an inner region with 3–5 layers of elongated thin-walled cells, 8–10 × 2–3 μm, K–. Asci narrowly cylindrical, without apical thickness, 8-spored, (160–)175–180(–195) × (8.5–)9.0–11.2(– 12.0) μm (n = 10). Ascospores hyaline, 8–12(–13)-septate, septa often hardly visible, filiform, straight or slightly curved, parallel to spirally twisted in the ascus, proximal ends rounded, distal end pointed, (160–)165–175(–180) × (2.4–)2.5–2.8(– 3.0) μm (n = 25), individual cells (13.2–)15.2–21.0(–23.8) μm (n = 30) long. Conidiomata not observed. Distribution, habitat and host range: The species is known from the Boliviano-Tucumano forest (2500 m a.s.l.) in Bolivia on corticolous Hypotrachyna species. Moreover, a specimen from New Zealand on Thelotrema species (reported as Thelotrema clathroporina) was reported (K-M000454728). This specimen was previously published under the name Nectria byssophyla by Rossman (1983). The examined specimen from Bolivia on Hypotrachyna sp. showed a strong pathogenic effect, forming discoloured infection spots. Specimens examined: Bolivia, Tarija Department, Aniceto Arce Province, Tariquía Flora and Fauna National Reserve, between la Cumbre and camamento los Alisos, 22º00’40.9”S, 64º35’48.9”W, 2485 m a.s.l., Boliviano-Tucumano forest with Alnus acuminata and cactus, on apothecial disk of Hypotrachyna sp. on trunk, 22 Jul. 2015, J. Etayo 32974 (hb. Etayo); 22º00’50.4”S, 64º36’24.3”W, on Leucodermia fertilis, 27 Jul. 2015, J. Etayo 29713 (LPB); ibid., on dead Hypotrachyna sp. on twig of Polylepis, 27 Jul. 2015, J. Etayo 29712 (hb. Etayo); ibid., J. Etayo 29822 (LPB). New Zealand, Waiwera Scenic Reserve, 20 m N of Auokland, on Thelotrema ‘chathroporina’ on bark of Rhopalostylis sapida, 30 Oct. 1981, J.K. Barthy H1275/81/YN2 (K-M000454728 = IMI 263194 a). Notes: This species is morphologically very similar to Rossmaniella filispora, but can be distinguished by the combination of morphological features and phylogenetic position. Rossmaniella cryptica has somewhat bigger, vivid orange ascomata, mostly in a group up to 4(–7) [in R. filispora (5–)7–12 ascomata in a group], bright orange ostiolate part without distinct hairs (distinct hairs present in R. filispora), somewhat shorter ascospores (160–)165–175(–180) μm [in R. filispora (165–)180–200(–210) μm] with longer, (13.2–)15.2–21.0(–23.8) μm, individual cells [in R. filispora (11.0–)11.5–13.7(–14.5) μm].