title: Umbilicaria americana
text: # Umbilicaria americana
  
  Umbilicaria americana, commonly known as frosted rock tripe, is a foliose lichen of rock faces.
  
  ## Description
  
  Umbilicaria americana has been described as looking like "grayish-white potato chips." 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.
  
  