Dermatocarpon americanum Vain.  
Family: Verrucariaceae
Dermatocarpon americanum image
Stephen Sharnoff  
Dermatocarpon americanum image
Joselyn Fenstermacher  
Dermatocarpon americanum image
Garry Neil  
Dermatocarpon americanum image
Garry Neil  
Dermatocarpon americanum image
Garry Neil