Common Toadskin Lichen 
Cookeina speciosa 
Copper Penny 
Coral Spot 
Cordyceps curculionum 
Cordyceps Militaris 
Cordyceps saussurei 
Cordyceps tenuipes 
Corky Bark Disease 
Crabseye Lichen 
Crescent Map Lichen 
Crimson cup 
Crinkled Snow Lichen 
Crocicreas coronatum 
Crumpled Rag Lichen 
Cryptothecia rubrocincta 
Cudonia circinans 
Curled Snow Lichen 
Daldinia childiae 
Dark Vegetable Caterpillar 
Dark-purple Earthtongue 
Dead Man's Fingers 
Dead Moll's Fingers 
Debariomyces hansenii