- 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