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Xanthoparmelia incerta (Kurok. & Filson) Elix & J. Johnst.
Family: Parmeliaceae
[Parmelia incerta Kurok. & Filson]
Xanthoparmelia incerta image
Thallus: foliose, tightly adnate to adnate, 3-8 cm in diam., irregularly lobate lobes: subirregular, elongate, plane to subconvex, contiguous to subimbricate, 1-2.5 mm wide, not lobulate; apices: subrotund, smooth to crenate, eciliate upper surface: yellowish green, smooth but becoming rugose with age, dull, epruinose and emaculate, without soralia, isidia, or pustulae medulla: white, with continuous algal layer lower surface: black, plane, sparsely rhizinate; rhizines: dark brown to black, simple, coarse, 0.2-0.4 mm long Apothecia: common, substipitate, 2-8 mm wide, laminal on thallus; disc: cinnamon-brown to dark brown; margin: smooth, epruinose asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid, 7-11 x 5-7 µm Pycnidia: common, immersed conidia: bifusiform, 6-7 x 1 µm Spot tests: upper cortex K-, C-, KC-, P-; medulla K+ yellow becoming dark red, C-, KC-, P+ red Secondary metabolites: upper cortex with usnic acid (major); medulla with salazinic acid (major) and consalazinic acid (minor) and often with norstictic and protocetraric acids (both trace). Substrate and ecology: on acidic rocks, often in open or partially shaded habitats World distribution: Australasia, southern Africa and North and South America Sonoran distribution: infrequent at intermediate to lower elevations in Arizona and Sonora. Note: Xanthoparmelia incerta is relatively uncommon in the Americas. The chemistry, lower surface and rhizines of X. incerta are reminiscent of X. tasmanica, but the thallus of the latter species is loosely adnate, lobulate and densely imbricate.