Brittonia 44, 3: 326 (1992).
Protolog: "TYPE: U.S.A. Tennessee. Carter Co.: Cherokee National Forest, Dennis Cove campground ca 4 mi SE of Hampton, elev. ca 800 m, oak woods, on thin soil over rock above stream, 12 May 1976, Harris 10730 (HOLOTYPE: NY; Isotypes to be distributed).
Type locality: USA, Tennessee, Carter County, Cherokee National Forest, Dennis Cove campground ca 4 mi SE of Hampton, oak woods, on thin soil over rock above stream, ca. 800 m, 12 May 1976, R. C. Harris 10730 (NY - holotype).
Type locality coordinates: 36°17'10"N, 82°10'19"W; 36.286111, -82.171944.
Barcode: Data lacking.
Thallus: dimorph. Primary thallus squamulose, forming colonies usually a few centimeters to a decimeter across but under optimal conditions as much as 0.5 m. Squamules crowded, forming cushions of vertically arranged or imbricate squamules (in depauperate specimens the squamules more distant), pale green above, white below, appressed to erect, somewhat recurved at tips when dry, (0.2-)0.5-0.8 mm long, dichotomously branched; loves linear, ca. 0.1 mm across; margins and tips crenate. Podetia absent or very short, ca. 0.1 mm, naked. Apothecia dark brown, obconical, to 1.0 mm diam., occasionally becoming compound; disk remaining flat; margin concolorous, slightly raised. Paraphyses simple, ca 2 µm across; terminal cell slightly enlarged, ca 3 µm. Asci 35-40 x 12-15 µm with eight, biseriate ascospores. Ascospores ellipsoid to long ellipsoid, 9.5-15 x 5-6 µm. Pycnidia brown, pyriform, sessile on squamules, ca. 0.1 mm diam. Conidia lunulate, thickened in middle or toward on end, 6-10 x 1 µm (Harris 1992: 326).
Photobiont: Data lacking.
Chemistry: Squamules containing perlatolic acid, fumarprotocetraric acid, traces of unknowns associated with perlatolic acid and accessory atranorin (Harris 1992: 326).
Ecology: On non-calcarous rock, or, less commonly, on a thin layer of soil over rock, a single collection on a hardwood tree, from near sea level in Maryland to 730 m in Tennessee (Harris 1992: 329).
Molecular data: Genbank
Distribution: Eastern North America. Database
Note:
Similis C. apodocarpa et C. caespiticia apotheciis sessilibus sed differt acidum perlatolicum contintenta, squamulis magnitudinibus intermediis,minus divisis quam C. caespiticia, et plerumque ad saxa nuda crescentia".