Button Everlasting 
Cabbage Thistle 
Calendula pachysperma 
Calendula palaestina 
Calico aster 
California Aster 
California Cudweed 
California goldenrod 
Calotis glandulosa 
Camphor-Weed 
Canada goldenrod 
Canada Hawkweed 
Canadanthus 
Canadian horseweed 
Cape marigold 
Cape Sable whiteweed 
Cape-Ivy 
Cardo Personata 
Cardoon 
Carlina frigida 
Carlina lanata 
Carlina libanotica 
Carlina racemosa 
Carline Thistle