Thallus: crustose, thin, composed of discrete, plane to convex areoles, up to 0.5-0.8 mm wide, or thicker with contiguous areoles up to c. 1 mm wide, uneven to verruciform surface: light gray to dark gray-brown, dull; margin: usually indeterminate, sometimes determinate; prothallus: dark, fimbriate when growing on rock; vegetative propagules: absent Apothecia: broadly attached becoming sessile, frequent, mostly not contiguous, up to 1-1.6 mm in diam. disc: black, sometimes pruinose, plane, rarely becoming convex thalline margin: concolorous with thallus, (0.05)0.1(-0.2) mm wide, entire or flexuose, persistent, or rarely with thin, limiting proper margin; excipular ring: otherwise absent thalline exciple: 70-200 µm wide laterally; cortex: 10-30 µm wide; epinecral layer: sometimes present, c. 10 µm thick; cortical cells: 4-7 µm wide, not pigmented; algal cells: up to 9.5-14 µm in diam.; thalline exciple: 100-180 µm thick below; cortex: 15-75 µm, hyphae intricate to columnar proper exciple: hyaline or frequently pigmented light gray-brown, 10-25 µm wide laterally, expanding to 15-35 µm at periphery hymenium: 80-115(-145) µm tall; paraphyses: 2.5-3 µm wide, not conglutinate, with apices up to 3.5-6 µm wide, heavily pigmented forming a dark-brown or reddish-brown epihymenium; hypothecium: hyaline, 40-135 µm thick asci: clavate, 70-85 x 17-27 µm, 8-spored ascospores: brown, 1-septate, ellipsoid, type A development, Teichophila-type, (18.5-)22.5-24(-28) x (9)11-12(-14) µm, sometimes inflated at septum, more so in K; lumina Physcia-, to Mischoblastia-like during development, becoming rounded (Pachysporaria-like), retaining thick apical walls; torus: absent; walls: ornamented, light to prominent in oldest spores Pycnidia: immersed in thallus, ostioles dark brown, 0.5-1 mm in diam. conidia: bacilliform, 4-5 x c. 1 µm Spot tests: K+ yellow, C-, KC-, P+ yellow Secondary metabolites: atranorin in cortex, zeorin in medulla. Substrate and ecology: on soil, decaying vegetation over soil, bark of coniferous and deciduous trees, wood, mosses over rocks, including shale, sandstone and igneous ones World distribution: a North American endemic belonging to the Californian floristic element along the Pacific coast from sea level to 1175 m in the coastal ranges of Baja California and California, with a northern outlier population near sea level in the Straits of Georgia region of British Columbia and Washington; rarely in the Cascades and Sierra Nevada Sonoran distribution: southern California to Isla Cedros, Baja California. Notes: Rinodina bolanderi has a very wide range of thallus morphology that must be attributed, at least in part, to the wide range of substrates it occupies. Rinodina bolanderi sometimes bears a superficial resemblance to R. confragosa with large apothecia but differs in possessing larger spores that belong to the Teichophila-, rather than the Physcia-type. The apothecia of R. bolanderi may be pruinose and this character may vary in different parts of a single collection. Specimens of R. bolanderi, labeled R. succedens and R. sophodes, collected by Howe and Hasse (NY), respectively, are the partial basis for reports of these species in Hasse (1913). Rinodina bolanderi is the first of four species with a Californian type of distribution that have a northern range extension into the Straits of Georgia region (Glew and Tønsberg 2000).