Thallus: crustose, thin to thick, continuous at first, quickly becoming rimose and then areolate, areoles up to 0.6-1.1 mm wide, with margins often raised to give a subsquamulose appearance, otherwise plane surface: ochraceous to brown, dull to shiny; margin: determinate; prothallus: lacking blastidia: sometimes present, proliferating from areole margins, 0.1-0.3 x 0.1-0.15 mm, comprised of consoredia, 60-80 µm in diam. Apothecia: erumpent, remaining adnate, frequent but rarely contiguous, up to 0.45-0.7 mm in diam. disc: dark brown to black, quickly becoming convex, sometimes half-globose thalline margin: typically concolorous with thallus, entire, sometimes blastidiate, 0.05-0.1 mm wide, frequently becoming excluded; excipular ring: often present: confluent thalline exciple: 50-80 µm wide laterally; cortex: 10-20 µm wide; epinecral layer: 5-20 µm wide; cortical cells: up to 4-6.5 µm wide, pigmented or not; algal cells: up to 11-16(-24) µm in diam. proper exciple: 5-20 µm wide laterally, expanding to 15-30(-40) µm wide at periphery hymenium: 80-100 µm tall; paraphyses: 2-3 µm wide, not conglutinate, with apices expanded up to 4-6 µm wide, pigmented brown forming a red-brown epihymenium, not immersed in dispersed pigment; hypothecium: hyaline or light yellow, 50-110 µm thick asci: clavate, 60-80 x 19-26 µm, 8-spored ascospores: brown, 1-septate, ellipsoid, type A development, Teichophila-type, (15.5-)19-20(-23.5) x (8)10-11(-13) µm, many elongate-ellipsoid at first, becoming broadly ellipsoid with apices often remaining rather pointed, sometimes swollen at septum but not more so in K, lumina small, Mischoblastia-like at first, then Physcialike, becoming rounded but retaining relatively thick walls (Pachysporaria-like); torus: present, heavily pigmented at maturity; walls: lightly ornamented or not, ornamentation less visible in darkly pigmented spores (Fig. 63) Pycnidia: immersed, ostioles pigmented brown; conidiophores: type I conidia: bacilliform, 3.5-4 x c. 1 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: often on eutrophic bark, especially Quercus, in water runnels on tree boles, or on horizontal branches, and other sites where dust accumulates, more rarely on wood or soil World distribution: a North American endemic belonging to the Californian floristic element with an oceanic distribution from Mayne Island, British Columbia (outlier) to northern Mexico Sonoran distribution: one of the most commonly collected Rinodina species in southern California, also from Baja California, from sea-level to 1475 m. Notes: Rinodina herrei typically possesses a plane to rimose-areolate thallus, the areoles having raised margins sometimes developing blastidia, and erumpent apothecia with discs rapidly becoming convex, giving well developed specimens a similar appearance to R. juniperina. The species are otherwise easily distinguished since R. juniperina has smaller, Physcia-type spores and has a continental distribution. Forms with the thalline margin excluded may resemble R. hallii because of the convex apothecia and the continuous or rimose thallus. However, R. hallii is well distinguished by its pruinose apothecia and larger, Physcia-type spores. Specimens growing on soil may resemble R. intermedia, a species easily distinguished by its three septate to pseudomuriform spores.