Rossmaniella filispora Darmostuk, Etayo & Flakus, 2025

Rossmaniella filispora Darmostuk, Etayo & Flakus , sp. nov. MycoBank MB 858387. Figs 3F, 3G, 9.

Etymology: Named after the filiform ascospores.

Typus: Bolivia, Chuquisaca Department, Belisario Boeto Province, close to Padilla between Nuevo Mundo and Santa Rosa , 18º57’12”S, 64º16’37”W, 1790 m a.s.l., transition between Boliviano-Tucumano forests and dry interandean vegetation, on corticolous Punctelia sp. , 16 Jul. 2015, A. Flakus 26556 (holotype KRAM L-74684, isotype LPB).

Ascomata perithecioid, ovoid to pyriform, not collapsed when dry, superficial, clustered in dense groups of (5–)7– 12 ascomata, pale to bring orange, ostiolate part the same colour as ascomatal surface, the lover part covered by hyaline tomentum, becoming more compact towards the top of ascomata, (220–)270–340(–365) × (190–)200–235(–270) µm (n = 20), sometimes individual ascomata has irregular form in the group due to compression by other ascomata. Ascomatal surface near the ostiole with short, cylindric, hyaline, 1–2-septate hairs, sometimes with inflated tips, 20– 55 × 5–7 μm. Ascomatal wall 20–35 μm thick, thicker at the upper part, hyaline to pale yellow, composed of two layers of cells: external layer composed of 3–5 layers of isodiametric to irregular, thin-walled cells, 5–7 μm in diam; an inner region with 3–5 layers of elongated thin-walled cells, 10–15 × 3–4.5 μm, KOH–. Asci narrowly cylindrical, without apical thickness, 8-spored, (164–)180–210(–230) × (8.5–)9.0–13.0(–14.4) μm (n = 15). Ascospores hyaline, 8–12-septate, septa often hardly visible, filiform, straight or curved, parallel to twisted in the ascus proximal ends rounded, distal end pointed, (165–)180–200(–210) × (2.8–)3.0–3.4(–3.8) μm (n = 30), individual cells (11.0–)11.5–13.7(–14.5) μm (n = 30) long. Conidiomata not observed.

Distribution, habitat and host range: This species was reported from scattered localities in Europe ( Spain) and South America ( Bolivia). Rossmaniella filispora is probably not a host-specific taxon as it was found on several lichen hosts belonging to the Parmeliaceae ( Flavopunctelia , Parmotrema , Hypotrachyna ), Peltigeraceae ( Peltigera ) and Ramalinaceae ( Phyllopsora ). This species did not show any pathogenic effect on the host.

Specimens examined: Bolivia, Chuquisaca Department, Belisario Boeto Province, close to Padilla between Nuevo Mundo and Santa Rosa , 18º57’06”S, 64º16’14”W, 1936 m a.s.l., transition between Boliviano-Tucumano forests and dry interandean vegetation, on Flavopunctelia sp. , 16 Jul. 2015, A. Flakus 26594 (LPB); ibid., 18º57’12”S, 64º16’37”W, 1790 m a.s.l., transition between Boliviano-Tucumano forests and dry interandean vegetation, on corticolous Flavopunctelia sp. , 16 Jul. 2015, A. Flakus 26557 (LPB); Cochabamba Department, Carrasco Province, Carrasco National Park, Korikaza close to Monte Punku, 17º33’30”S, 65º16’32”W, 2880 m a.s.l., lower montane Yungas cloud forest, on corticolous Parmotrema sp. , 27 Nov. 2014, J. Etayo 29951 (LPB); Tarija Department, Burnet O’Connor Province, close to los Pinos, old road between Entre Ríos and Tarija, 21º24’50”S, 64º18’33”W, 2149 m a.s.l., Boliviano-Tucumano forest dominated by shrubs, with Alnus acuminata , Podocarpus and Ericaceae , on Phyllopsora sp. , 29 Jul. 2015, A. Flakus 27468 (KRAM L-74686, LPB); ibid., on Parmotrema sp. , M. Kukwa 16861a (UGDA L, LPB); ibid., 21º27’48”S, 64º13’24”W, 1943 m a.s.l., Boliviano-Tucumano forest with Podocarpus , on corticolous Punctelia sp. , 28 Jul. 2015, A. Flakus 27389a (LPB); ibid., 21º25’07”S, 64º18’50”W, 2190 m a.s.l., Boliviano-Tucumano forest dominated by shrubs, Andino Montano belt, on Peltigera didactyla , 29 Jul. 2015, J. Etayo 30600 (LPB); ibid., 112 km from Tarija on the way to Entre Ríos, near San Diego, 21°26’28”S, 64°14’37”W, 1620 m a.s.l., Tucumano-Boliviano montano forest, on Parmotrema sp. on twig, 9 Aug. 2012, J. Etayo 28594 (hb. Etayo); near Soledad, 21°39’52”S, 64°07’22”W, 1700 m, Tucumano-Boliviano montano forest, on Parmotrema reticulatum on twig, 11 Aug. 2012, J. Etayo 28777 (LPB). Spain, Guipuzcoa, Peñass de Aia, Lesakako Bidea, antes del tunel, 43 16’25”N, 1 47’35.5”W, 500 m a.s.l., on Hypotrachyna revoluta on Fagus sylvatica , 31 Aug. 2019, J. Etayo 31862 (hb. Etayo).

Notes: The species is morphologically very similar to Rossmaniella cryptica , but it can be distinguished by specific morphological features and its phylogenetic position. However, R. filispora does not seem to be a rare species in the tropical forests of Bolivia and is known from several localities.