Catonia blattarioides Cass. accepted as Crepis pyrenaica (L.) Greuter (original description)
Celmisia rotundifolia Cass. accepted as Capelio tabularis (Thunb.) B.Nord. (original description)
Centaurium moschatum Cass. accepted as Amberboa moschata (L.) DC. (original description)
Centaurium officinale Cass. (original description)
Centaurium suaveolens Cass. accepted as Amberboa moschata (L.) DC. (original description)
Centrapalus Cass. (original description)
Centrapalus galamensis Cass. accepted as Centrapalus pauciflorus (Willd.) H.Rob. (original description)
Centratherum Cass. (original description)
Centratherum punctatum Cass. (original description)
Ceratocephalus Cass. accepted as Bidens L. (original description)
Ceratocephalus pilosus Rich. ex Cass. accepted as Bidens pilosa L. (original description)