Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: crustose, thin or thick, areolate, areoles contiguous, up to 0.5-1 mm wide, margins sometimes raised, plane or somewhat rugose surface: white, ochraceous to brownish, dull or shiny; margin: determinate; prothallus: absent; vegetative propagules: absent Apothecia: erumpent, becoming adnate, usually one per areole, frequent, up to (0.3-)0.6-0.7 mm in diam. disc: concave to plane or slightly convex, black, mostly pruinose thalline margin: concolorous with thallus, 0.05-0.1 mm wide, entire, persistent or becoming partly excluded; excipular ring: sometimes present, raised thalline exciple: (40-)60-120 µm wide; cortex: 5-20 µm wide; epinecral layer: 10-30 µm wide; cortical cells: up to 4.5-7.5 µm wide, pigmented or not; algal cells: up to 10-20 µm in diam. proper exciple: 10-15 µm wide laterally, expanding to 15-50 µm at periphery hymenium: 70-90 µm tall, paraphyses: 2-3.5 µm wide, not conglutinate, with apices expanded up to 4-6.5 µm wide, darkly pigmented, often including the penultimate septa, immersed in dispersed pigment forming a red-brown epihymenium; hypothecium: hyaline to pale yellow, 70-100 µm thick, extending into a stipe below asci: clavate, 50-65 x 17-23 µm, 8-spored ascospores: brown, 1-septate, broadly ellipsoid, type A development, Bicincta-type, (10.5-)13-14(-17) x (7.5-)8.5-9(-10.5) µm, outer wall thickened at septum and apices when young, lumina quickly becoming rounded, spores later becoming waisted, pigmented band around each cell; torus: absent, walls: not ornamented Pycnidia: not seen Spot tests: all negative Secondary metabolites: zeorin. Substrate and ecology: on calcareous rocks World distribution: scattered in Scandinavia, mountains of southern and central Europe, North Africa, Australia, New Zealand, and western North America Sonoran distribution: southern California. Notes: Rinodina luridata is characterized by its small, Bicincta-type spores, its usually ochraceous and areolate thallus with innate to adnate apothecia. Rinodina luridata has been compared to R. lecanorina (A. Massal.) A. Mas-sal. by Mayrhofer et al. (1990), a species with larger spores, thicker thallus and larger apothecia that is not known from North America.