Carolina Anemone 
Carolina Coralbead 
Carolina Larkspur 
Ceratocephala falcata 
Chinese barberry 
Chinese Globeflower 
Chinese Meadow-rue 
Chocolate Vine 
Christmas rose 
Clematis integrifolia 
Clematis lanug 
Clematis millefoliolata 
Clematis patens 
Clematis vitalba 
Clematis zeylanica 
Climbing corydalis 
Cocculus pendulus 
Colorado blue columbine 
Columbian monkshood 
Columbian windflower 
Common clematis 
Common Columbine 
Common Fumitory 
Common Poppy