Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: thin, warted-areolate, rimose or rarely endosubstratal areoles: scattered or contiguous, strongly convex or with irregular surface, 0.05-0.25 mm in diam., often confluent or forming a rimose crust with areoles 0.3-0.6 mm in diam. surface: grayish beige to pale yellow; dull, esorediate cortex: poorly developed, 5-10 µm high medulla: mostly lacking; algal layer: 30-60 µm high Apothecia: rounded to somewhat deformed, often in groups of 3-5, sessile, with a weakly constricted base or appressed, 0.15-0.45 mm wide disc: ochre to reddish brown, sometimes with a pink hue due to a fine, white pruina, plane or weakly convex margin: weakly prominent and soon excluded or lacking from the beginning, exciple: ochre to reddish brown at the outer edge or near the hymenium, hyaline or pale yellow within, laterally 15-30 µm wide, basally 15-50(-65) µm wide, composed of branched and anastomosing, radiating hyphae with 0.7-1 µm wide lumina and apical cells with lumina 3-6 µm wide epihymenium: yellowish to reddish brown, composed of paraphysal tips and ±sparse granules, 5-10 µm high hymenium: hyaline, 5060(-70) µm high; paraphyses: basally hyaline, with lumina 0.7-1.2 µm wide, apically mostly with pale brown walls and lumina 2-4.5 µm wide, weakly to moderately branched (mainly below apical cells) and anastomosing subhymenium: hyaline, 15-55 µm thick hypothecium: hyaline or pale yellow, 0-100 µm thick asci: clavate, Lecidella-type with an I+ blue tholus containing a lighter blue, broadly rounded axial body, 8-spored ascospores: hyaline, simple, broadly ellipsoid, (7-)8.6-11.1(-13.5) x (4-)4.9-6.1(-7) µm Pycnidia: not seen Spot tests: thallus K-, C± orange, P-, UV± dark orange Secondary metabolites: atranorin and xanthones. Substrate and ecology: on bark, often on twigs of deciduous trees and shrubs, rarely on wood, between 50 and 500 m (one collection from 2550 m) World distribution: North America and Europe Sonoran distribution: Baja California, southern California, and Durango. Note: The minute, pale apothecia of Lecidea varians distinguish it from all other species treated here.