Thallus crustose, light gray to dark greenish gray, discontinuous or continuous becoming rimose or rimose-areolate; vegetative diaspores absent. Photobiont chlorococcoid alga, cells 8-13 μm. Ascomata lecanorine apothecia, immersed to sessile, frequent, scattered, 0.4-1.0 mm diam. Disk flat to slightly convex, dark brown to black; thalline margin sometimes poorly developed; exciple light brown, 10-30 μm wide; epithecium light to red-brown; hymenium hyaline, 60-120 μm high, not inspersed with oil droplets; hypothecium hyaline, tapering into a stipe. Asci globose clavate, 45-75 x 14-30 μm, 8-spored. Ascospores hyaline to brown, broadly ellipsoid, 2-celled, Pachysporaria-type II, 12-23.5 x 6.5-10.0 μm. Pycnidia reddish-brown, often half-exposed; conidia bacilliform, 3.0-4.5 x 1.0-1.5 μm.
Chemistry. Spot tests all negative, secondary metabolites not detected.
Substrate and Habitat. On hardwood twigs and branches, in hardwood and mixed forests.
Distribution. Eastern North America; also central and South America; in North Carolina occurs in the coastal plain and piedmont ecoregions.
Müller, J. (1889) Observationes in Lichenes Argentinenses a Doctt. Lorentz et Hieronymo lectos et a Dr. A de Krempelhubero elaboratos. Flora (Regensburg). 72: 62-68.
Sheard, J.W. (2010) The Lichen Genus Rinodina (Lecanoromycetidae, Physciaceae) in North America, North of Mexico. National Research Council of Canada, NRC Research Press, Ottawa. 246 pp.