Salted Shield Lichen 
Sea Ivory 
Shingled rock shield lichen 
Shrubby Cup Lichen 
Smooth Horn Lichen 
Smooth-footed Powderhorn 
Soft Strap Lichen 
Southern Soldiers Lichen 
Squamarina cartilaginea 
Squamarina gypsacea 
Star-tipped Reindeer Lichen 
Stereocaulon ramulosum 
Sterocaulon vesuvianum 
Thorn Cladonia 
Toy Soldiers 
Transcend cup lichen 
Trumpet Lichen 
Tube Lichen 
Tuckermannopsis americana 
Tuckermannopsis fendleri 
Turban Lichen 
Umbilicaria phaea 
Usnea cornuta 
Usnea hirta