Description

 Thallus: foliose, tightly adnate, 3-7 cm in diam., irregularly lobate; lobes: sublinear, short, plane to subconvex, separate and contiguous to slightly imbricate, 0.6-1.2 mm wide, not lobulate; apices: subrotund, smooth to crenate, eciliate; upper surface: yellow-green to brownish olive green, smooth but becoming strongly rugose-bullate with age, dull to somewhat shiny, epruinose and emaculate, without soralia, isidia, or pustulae; medulla: white, with continuous algal layer; lower surface: black, plane, sparsely rhizinate; rhizines: black, simple, 0.2-0.4 mm long; Apothecia: common, adnate to substipitate, 1.5-2 mm wide, laminal on thallus; disc: cinnamon-brown to dark brown; margin: smooth, epruinose; asci: clavate, 8spored; ascospores: hyaline, simple, ellipsoid, 9-11 x 5-6 µm; Pycnidia: common, immersed; conidia: bifusiform, 4-5 x 0.5 µm; Spot tests: upper cortex K-, C-, KC-, P-; medulla K+ yellow to orange, C-, KC-, P+ yellow; Secondary metabolites: upper cortex with usnic acid (major); medulla with stictic acid (major), constictic acid (minor), and cryptostictic, menegazziaic and norstictic acids (all trace).; Substrate and ecology: on acidic rocks, often in open, arid to woodland habitats; World distribution: southwestern North America; Sonoran distribution: occasional at low to intermediate elevations in Arizona and western Chihuahua.; Notes: Although recognized by Hale only from New Mexico, we have now found it at several localities in the Sonoran region. The presence of stictic acid as the major medullary substance, its lack of asexual reproductive structures and black lower cortex are diagnostic features of X. neoconspersa.