Abrothallus eriodermae Suija, Etayo & Pérez-Ortega, 2015

Suija, Ave, Ríos, Asunción De Los & Pérez-Ortega, Sergio, 2015, A molecular reappraisal of Abrothallus species growing on lichens of the order Peltigerales, Phytotaxa 195 (3), pp. 201-226 : 210-211

Abrothallus eriodermae Suija, Etayo & Pérez-Ortega , sp. nov.

Mycobank MB#809368; Fig. 5

Diagnosis:—Lichenicolous fungus on Erioderma spp. that differs from the rest of Abrothallus species by having subcylindrical asci with two-celled ascospores with dimensions of 9–(9.8)–11.5 × 3.5–(4.1)–4.5 μm which split into part-spores within the ascus, and by having superficial subglobose to lageniform pycnidia.

Type:— LA REUNION (Indian Ocean). Bebour forest, river with large boulders and surrounding shrubs, elev. 1330–1340 m (21º06.789’S 55º34.036’E), on Erioderma papyraceum , 27 May 2008, E. Sérusiaux (holotype LG).

Mycelium immersed, K/I–. Ascomata superficial on thallus and ascomata of Erioderma spp. , black, green pruinose, convex, 180–(265)–540 μm (n=10), up to 120 μm high. Hymenium hyaline in lower part, greenish to olive green in upper part, ca. 65 μm high, covered with pale brown crystals, K+ greenish, N ± slightly violet; exciple ca. 65 wide in vertical section; hypothecium light brown to medium brown; hypothecial cells rectangular (textura angularis), 4–6 × 3–6 μm (n=10). Asci bitunicate in structure, subcylindrical to narrowly clavate, 40–57 × 6–9 μm. Ascospores 2-celled, medium brown, asymmetric, 9–(9.8 ±0.6)–11.5 × 3.5–(4.1 ±0.3)–4.5 (upper cell)/3–(3.5 ±0.4)–4 (lower cell) μm (n=20), l/w (upper cell) ratio = 2–3.1, ascospore separate into 16 part-spores inside the ascus. Interascal filaments unequally dichotomously branched, the tip not or only slightly widened. Anamorph present, pycnidial. Pycnidia superficial, subglobose to lageniform, ca. 100 μm wide, with distinct white drop above consisting of conidia in muscilage. Conidiogenous cells hyaline, lageniform, lining the cavity, 7–(8.5 ±1.5)–11 × 2.5–(2.7 ±0.3)–3 μm (n=19). Conidia simple, hyaline, broadly ellipsoid to almost globose, with truncated base, 4–(4.5 ±0.4)–5 × 3–(3.7 ±0.5)–5 μm (n=20), l/w ratio 1.0–1.5. No visible damage observed.

Etymology:—The epithet eriodermae refers the host genus and was chosen based on the herbarium specimens in UPS signed but not published by Rolf Santesson.

Notes:— Abrothallus eriodermae has been collected from North America (Alaska), South-America ( Chile, Colombia, Ecuador), Jamaica (Greater Antilles) and Le Reunion island (Indian Ocean) from various Erioderma species ( Erioderma chilense , E. sorediatum , E. papyraceum , E. wrighti i, Erioderma sp. ).

There is one Abrothallus specimen on Erioderma sp. from China (UPS(L-19086)53058) signed by Rolf Santesson as A. eriodermae var. eriodermae ined. (= A. sp. 1 in this paper) which differs from A. eriodermae mainly by having larger ascospores, 16–(18.3 ±1.3)–21 × 7–(8 ±0.7)–9 (upper cell)/6–(6.8 ±0.6)–8.0 (lower cell) μm (n=20; Table 2). Etayo (2002) reported another Abrothallus species (as A. aff. secedens ) growing on Erioderma from Colombia, however the dimensions of ascospores (11.5–14 × 5–5.5 μm) were slightly larger than those in A. eriodermae , and ascomata were apparently epruinose.

The type specimen is accompanied by similar truncated conidiomata with a distinct white drop above (dry mass of conidia), as described by Zhurbenko & Dillman (2010) in the Alaskan specimen (LE-260047), but the asexual morph was not found in the other studied specimens.

Additional specimens examined: — USA. Alaska: on Erioderma sorediatum, K. Dillmann ko 2001-299 (LE-260047); JAMAICA. Ex Merill Lich. Exc. 8, sine loco, on E. wrightii, February-March 1906 , C.S. Cummings, det. R. Santesson ( UPS); CHILE. Valdivia: Los Lagos, Enco, on shrubs ( Baccharis ) in the outskirts of a rainforest near shore of the lake, on E. leylandii subsp. chilense (= E. chilense ), 27 September 1940, R. Santesson S367 ( UPS (F-156134)450259); COLOMBIA. Pantano de los Martos, on Erioderma sp. , 28 September 2012, J. Paal (TU-65983); Nariño: Pasto, corregimiento El Encano, vereda Sta. Isavel, S lago L Cocha (Guamues), pásamo azonal, elev. 2700 m (0.59ºN 77.09ºW), 30 July 1998, Churchill, Etayo 16615, Muñoz & Ramírez (hb. Etayo); ibid., 30 July 1998, J. Etayo 16615 & 16632 (hb. Etayo); ECUADOR. Sierra sur: Loja, Cajanuma, Parque Nacional Podocarpus, bosque nublado y páramo, montañas “nudo de Sabanilla”, elev. 2750–3000 m, on Erioderma sp. , 4 August 1999, J. Etayo 20143 & Z. Palice (hb. Etayo).

Figures

FIGURE 5. Abrothallus eriodermae (holotype). a: ascomata mixed with lageniform pycnidia; b: pycnidia; c: ascus and ascospores; d: part-spores; e: conidiophores with conidia; e: conidia; f: ascospores. Scale bars: a–b = 500 μm; c–f = 10 μm; g = 5 μm