Species: Umbilicaria angulata

Thallus to 9 cm, monophyllus, thick, rigid, round to irregular often divided into overlapping lobes, the umbo puckered in between creases and folds; upper side smooth to obscurely wrinkled and cracks with occasional coarse black cracks, dull or subshiny, dark brown or blotched with grayish olive, with thin pruinosity toward the margins; underside black or dark brown, usually covered with a tangled mat of coarse cylindrical or flattened granulose rhizinae, the lower cortex black and coarsely papillate-verrucose. Apothecia common, adnate or partly immersed more or less angular; disk black with a few gyri, margin thick, the gyri sometimes becoming beaded, the surface dull or shiny (Thomson 1984).