Rossmaniella cryptica Darmostuk, Etayo & Flakus, 2025

Rossmaniella cryptica Darmostuk, Etayo & Flakus , sp. nov. MycoBank MB 858386. Figs 3I, 4A, 8.

Etymology: Named after Rossmaniella filispora .

morphological similarity to

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 263194a).

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].