Primary thallus: mostly forming only a thin, varnish-like film over the substrate, inconspicuous, often scarcely visible podetia: absent or very short, often immersed in the substrate, up to 1 mm tall, 0.5-1 mm diam., narrow at the base, wider above, finally going over the disc margin, weakly but distinctly channeled or longitudinally folded, mostly concolorous with the apothecia. surface: emerald green to gray when fresh, becoming brownish to beige, mostly smooth, scarcely cracked, rarely with calcium oxalate excretions, without soredia Apothecia: solid in longitudinal section, rose, pale rose to pale beige or ivory white, round, 0.5-2 (-3) mm diam.; disc: plane to uneven, often slightly funnel-shaped, pruinose in the center; margin: sometimes visible, narrow, swollen, rose-red [in non-Sonoran material], becoming convex towards the inside; hymenium: c. 120 µm, the upper 20 µm with lichen substances asci: 65-80 x 8 µm wide, (4-) 8-spored ascospores: ovoid to oblong-ellipsoid, hyaline, simple, (9-) 1.7 ± 1.38 x 4.58 ± 0.64 µm, L:W = 3 Spot tests: thallus and apothecia K+ yellow, C-, KC+ orange, P+ orange, UV+ orange Secondary metabolites: baeomycesic and squamatic acids (both major), and barbatic acid (accessory). Substrate and ecology: on rock, soil, loam, loamy rock walls, sandstone World distribution: pantropical to subtropical, particularly in the Americas, Asia and Australasia Sonoran distribution: known from several collections from a single locality in central Sinaloa, 2300-2320 m, on soil over acidic rock in pine-oak forest, and on road bank. Notes: This species is characterized by an inconspicuous, smooth thallus that contrasts with the pale, rose-colored, plane, small, almost sessile, rounded apothecia.