Centaurium portense 
Ceropegia attenuata 
Ceropegia dimorpha 
Chinese Ixora 
Cionura 
Clasping Milkweed 
Climbing dogbane 
Coffea arabica 
Common Centaury 
Common frangipani 
Common Gardenia 
Common Milkweed 
Conkerberry 
Coprosma robusta 
Corn Cleavers 
Crosswort 
Crown Flower 
Crucianella ciliata 
Crucianella maritima 
Cruciata articulata 
Cruciata taurica 
Cuayote 
Cynanchum perrieri 
Cynanchum viminale