- corn mayweed
 - cat's foot
 - catnip
 - canna
 - Coptis trifolia groenlandica
 - celandine
 - Crambe maritima
 - Chrysanthemum balsamita
 - celery root
 - celeriac
 - Celosia cristata
 - coriander plant
 - Cassia marilandica
 - cottonweed
 - crowfoot
 - cardamom
 - cayenne jasmine
 - cardamon
 - creeping zinnia
 - Chrysanthemum parthenium
 - Collinsonia canadensis
 - cast_iron plant
 - carrion flower
 - campanula
 - Cephalotus follicularis
 - caryophyllaceous plant
 - Chinese forget_me_not
 - crotalaria
 - cultivated celery
 - clammyweed
 - Cape periwinkle
 - chaenactis
 - costmary
 - chickweed
 - columbo
 - Cnidoscolus urens
 - Chamaemelum nobilis
 - Coptis groenlandica
 - comfrey
 - Chinese parsley
 - common amsinckia
 - chervil
 - coleus
 - Celosia argentea
 - chicory plant
 - common cockscomb
 - Cuminum cyminum
 - coral necklace
 - carrot
 - contempt