Mycobank MB 519464
Thallus ecorticate, smooth to rimose, surface beige to gray, often with a greenish tinge, matt, esorediate, up to 10 mm in diam. Photobiont trebouxioid. Apothecia sessile with a broad base or slightly constricted basally, 0.3–0.6 mm diam.; margin usually not visible, rarely as a lighter rim around the disc; disc weakly to moderately convex, white to pale ochre, matt, epruinose. Excipulum hyaline, 30–40 µm laterally, 20–45(–90) µm wide basally, of strongly gelatinized, diverging hyphae with 1–2.5 µm wide lumina, lumina of apical cells 1.5–3.5 µm wide, partly free and with thick gelatinous outer walls. Hymenium hyaline, 50–60 µm. Paraphyses colourless, weakly to moderately branched and anastomosing, mostly in basal parts of the hymenium and the subhymenium, lumina 0.8–1.2(–1.5) µm wide, apical cells with lumina of 1–3(–4) µm. Subhymenium hyaline, 20–40(–55) µm high. Hypothecium 20–40(–80) µm high, of densely entangled, narrow hyphae with lumina 0.8–1.2 µm wide, strongly gelatinised, but with characteristic lacunae 3–10 µm wide. Asci Biatora-type, 8-spored. Ascospores (0–)3-septate, (11–)12.4–16.5(–19.5) x (3.3–)4.2–4.8(–5.5) µm, hyaline, narrowly ellipsoid, sometimes slightly bent. Pycnidia not found. Secondary chemistry: no substances detected by TLC.
Biatora epirotica most closely resembles B. pallens (Kullh.) Printzen in having 3-septate ascospores and excipular hyphae with broad lumina. Biatora pallens is easily distinguished by its narrower ascospores ( 10.5–17.0 x 2.5–4.0 µm), a more shallow hymenium ( 30–40 µm tall) and the presence of usnic acid. Three more species of Biatora with predominantly 4r-celled spores are known: B. aegrefaciens Printzen, B. nobilis Printzen & Tønsberg and B. rufidula (Graewe) S. Ekman & Printzen. All three species have excipular hyphae with narrowly elongate lumina and orange-brown apothecia. In B. aegrefaciens and B. rufidula, the exciple reacts I+ violaceous. Biatora nobilis and B. aegrefaciens also have broader ascospores (5.0–8.5 µm wide). The known distributional range of Biatora epirotica is centred around the Black Sea region, a well known Tertiary and Pleistocene refugial area. Other species of Biatora with a similar distributional range include B. bacidioides Printzen & Tønsberg, B. pontica Printzen & Tønsberg and B. longispora (Degel.) Lendemer & Printzen. The latter two are also known from eastern North America and East Asia, and B. epirotica should be looked for in those regions.
The epithet is derived from Epirus, the geographical region on the Balkans where most of the material was collected.
Biatora epirotica has been found on twigs of Abies borisii-regis, A. nordmanniana, Laurus nobilis, Ostrya carpinifolia, Quercus coccifera, and trunks and dead twigs of young Picea orientalis on the southwest Balkans and along the Turkish Black Sea coast. It mostly occurs in mountain areas with high humidity and extensive cyanolichen communities at elevations of 450 to 1500 m.
Type:—GREECE: Epirus, Nomos Ioanninon, Tzoumerka, near Palaiochorion; 39°30’N, 21°05’E, 776 m; corticolous on twigs of Abies borisii-regis; Apr 2006, Spribille 19735 (holotype FR, isotypes ATHU, GZU, further isotypes to be distributed as exsiccatae).
Additional specimens examined (paratypes):—GREECE. Epirus, Nomos Ioanninon, Dimos Tzoumerka, near Kataraktis, shrine to Profitis Ilias; Spribille s.n. (hb. Spribille); ibid., near Palaiochorion, Spribille 16283 (GZU); ibid., above Pramantha, Spribille 19818 (GZU); ibid., W of Arachthos River above Politsa, Spribille 19861 (GZU). Epirus, Nomos Ioanninon, Dimos Koinotita Vovousas, Zagori region, Pindos Mts., above Aoos River, S of Vovousa; Spribille 16001 (GZU). TURKEY. Bolu vilayet, S of Karacasu; Spribille 23136 (GZU). Kars vilayet, lake Karagöl NE of Savsat; Printzen 6468, 6495 (BG).
Biatorae pallentis similis sed ascosporis majoribus et hymenio altiore differt.