Umbilicaria americana, commonly known as frosted rock tripe, is a foliose lichen of rock faces.
Umbilicaria americana has been described as looking like "grayish-white potato chips."[1] The upper surface is gray with the appearance of white dusting. The lower surface is black. The lobes are 2 to 7 cm in diameter.[2]
Umbilicaria americana, commonly known as frosted rock tripe, is a foliose lichen of rock faces.
