Thallus: warted-areolate to subsquamulose areoles: +isodiametric in outline and strongly convex, or irregularly incised and subsquamulose, 0.10-0.55 mm in diam. surface: pale green to dark olive green, often with brownish or ochre parts, dull, mostly esorediate, rarely sorediate in parts soredia: if present, globose, 15-20 µm in diam., very rarely (and probably only derived from abraded parts of the thallus) in punctiform, light green or beige soralia 0.10- 0.35 mm in diam. cortex: often with brownish hyphae Apothecia: mostly single, more rarely in small groups, 0.3-1.2 mm in diam., rounded or deformed, sessile with constricted base, rarely semi-immersed between thallus areoles, flat to moderately, or rarely strongly convex, epruinose disc: red-brown, dull margin: concolorous with disc, ±level with disc, soon excluded or lacking from the beginning exciple: red-brown (K-, N-) along rim, otherwise hyaline, laterally 40-85 µm wide, composed of radiating hyphae with +cylindrical lumina and scattered rounded cells with thick gelatinous sheaths epihymenium: red-brown (K-, N-) hymenium: hyaline below, 50-70 µm tall; paraphyses: with lumina of 0.7-2 µm wide, richly branched in upper part and moderately anastomosed, with apices: slightly thickened and with lumina 1-2.5(-4) µm wide subhymenium: hyaline, 35-60 µm thick hypothecium: hyaline, 30-200 µm thick asci: clavate, Porpidia-type, 8spored ascospores: hyaline, simple, fusiform or broadly ellipsoid, (10-)11.2-13.8(-16) x (3.5-)4.6-6(-7) µm, with a warted perispore 0.5 µm wide Pycnidia: not observed Spot tests: all negative Secondary metabolites: 2-3 unidentified fatty acids. Substrate and ecology: on (often rotten or charred) wood, in and around deep bark crevices at the base of conifers, preferrably Pseudotsuga menziesii and Calocedrus decurrens, 1275-2950 m World distribution: mountain ranges of western North America and Spain Sonoran distribution: mountain ranges of Arizona, above c. 2000 m, and southern California at 1250 to 1750 m. Notes: Lecidea holopolia is easily identified by its scattered, rounded excipular cells with thick, unpigmented sheaths. Most North American material was misidentified as Biatora vernalis. The species Mycobilimbia olivacea has recently been described from Europe. However, the Porpidia-type ascus, presence of a distinct, warted perispore, branched and anastomosed paraphyses with swollen, brown apical cells, and rather thick-walled photobiont cells packed in small clusters distinguish L. holopolia from Biatora as well as Mycobilimbia.