Synonyms: Biatora atroviridis (Arnold) Hellb.; Biatorina subglobulosa (Nyl.) Arnold; Catillaria globulosa var. subglobulosa (Nyl.) Zahlbr.; Catillaria prasina f. ocelliformis (Nyl.) Erichsen; Lecidea atroviridis (Arnold) Th. Fr.; Lecidea atroviridis f. ocelliformis (Nyl.) Blomb. & Forssell; Lecidea ocellaris Vain.; Lecidea subglobulosa Nyl.; Lecidella turgidula var. atroviridis Arnold
Distribution: N - TAA (Printzen 1995, Thor & Nascimbene 2007, Nascimbene & al. 2007b, 2022, Nimis & al. 2015), Piem (Isocrono & al. 2004). S - Cal (Puntillo 1996).
Description: Thallus crustose, endosubstratic or very thinly episubstratic, grey to olive green, continuous to rimose-areolate, developing on a dark grey hypothallus. Apothecia biatorine, rounded or slightly irregular in outline, broadly sessile, 0.25-0.6(-0.8) mm across, with a dark grey to blue-black, epruinose, flat to moderately convex disc, and a thin, often paler, finally excluded proper margin. Proper exciple colourless to pale brown in outer rim, the inner part olive-brown, 30-85 μm wide; epithecium poorly differentiated from the hymenium, sometimes with dark brown patches; hymenium colourless or pigmented as the epithecium, 30-40(-50) µm high; paraphyses simple or sparingly branched in upper part, 1-1.5 µm thick, the apical cells slightly swollen; hypothecium dirty olive, mottled with green-black to dark brown patches, N+ violet. Asci 8-spored, clavate, with a K/I+ blue apical dome penetrated by a narrow, K/I– apical cushion surrounded by a narrow, deeply K/I+ blue zone, the wall K/I- but surrounded by an I+ red-brown, K/I+ blue outer layer, the ocular chamber relatively small, Biatora-type. Ascospores 1-celled (rarely 1-septate), hyaline, narrowly ellipsoid, (7.5-)9.5-14(-20) x (2.5-)3-4(-5.5) µm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P+ red. Chemistry: thallus with argopsin; axciple and hypothecium with the Bagliettoana-green pigment.
Note: a boreal-montane species found on the bark of mostly young, deciduous and coniferous trees in montane to subalpine forests. It is included in the Italian red list of epiphytic lichens as “Endangered” (Nascimbene & al. 2013c).