Japewiella tavaresiana

Thallus immersed to superficial, thin, whitish; prothallus black, thin. Apothecia 0.2–0.7 mm diam., flat, regular, pale to dark red-brown; true exciple persistent, colourless within, edge and epithecium pale red-brown, K+ dull brown, N–; hymenium 60–70µm; hypothecium 20–45 µm tall, colourless, I+ blue; paraphyses branched below, occasionally anastomosed, apices slightly thickened with brown caps. Asci 55–65 × 15–20 (–28) µm, ± Lecidella-type with a broad apical cushion. Ascospores 13–18 (–22) × 7–11 µm, ellipsoidal, thick-walled, the wall homogeneous. Thallus C–, I–, K± faint yellow, KC–, Pd–, UV– (atranorin).

Japewiella tavaresiana is often found with Lecanora jamesii. This species and Lecidea erythrophaea have previously been misidentified as Lecidea tenebricosa (Ach.) Nyl. (1861) by British authors. L. erythrophaea differs in its narrower, thin-walled ascospores. Traponora varians is superficially similar but is distinguished by the KC+ orange, VU+ pinkish thallus and smaller, thin-walled ascospores, 7–13.5 × 4–7 µm in size.