Thallus: areolate, 0.10-0.15 mm thick, usually less than 1 cm across, with comparatively broad fissures, with abrupt margins, without an apparent prothallus areoles: subangular, plane, 0.2-0.4 mm wide, with pale to dark brown sidewalls surface: brown, dull, epruinose, smooth to somewhat rough anatomy: upper cortex composed of 1-2 layers of brown cells, overlain by a c. 10 Ám thick, amorphous epinecralic layer; algal cells: 7- 12 Ám in diam., distributed over most of the thallus; without an alga-free medulla or dark basal layer Perithecia: situated at the edge of, or between the areoles, subglobose, black, distinctly elevated, with convex or slightly conical apices; ostiole inconspicuous; exciple: subglobose, 0.15-0.20 mm wide, brown, 15-20 Ám thick; involucrellum: appressed to the exciple, extending to exciple-base level and incurved beneath, apically and laterally c. 50 Ám thick, thinner at base; periphyses 15-20 Ám long, simple asci: clavate, 45-55 x 14-18 Ám, 8-spored ascospores: hyaline, simple, ellipsoid, 11-15 x 5-7(-8) Ám Pycnidia: unknown Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: epilithic, on calcareous rocks and sandstone World distribution: Europe, North Africa, Australia Sonoran distribution: two collections known from Arizona (Coconino and Yavapai Counties). Notes: The Sonoran specimens of Verrucaria minor agree well with the European collections. This taxon is regarded as a variety of Verrucaria lecideoides by most authors, but it merits species rank. It is distinguished from Verrucaria lecideoides by its smaller thalli with epruinose surfaces and distinctly emergent to almost superficial perithecia. Verrucaria fraudulosa differs in having convex areoles, larger perithecia, and longer spores.