Corn marigold 
Cornflower 
Corsican Everlasting 
Corymbflower tansy 
Corymbose Distaff Thistle 
Cota palaestina 
Cotton Thistle 
Cotton weed plant 
Cousinia dayi 
Cousinia hermonis 
Cousinia moabitica 
Cousinia rotundifolia 
Cousinia takhtajanii 
Coyote Brush 
Craspedia glauca 
Creeping Bellflower 
Creeping Groundsel 
Creeping Thistle 
Crepis aculeata 
Crepis barbigera 
Crepis robertioides 
Crepis sancta 
Crepis syriaca 
Cretanweed