| Campion, Red | SILENE DIOICA |
| Campion, White | SILENE PRATENSIS |
| Cherry, Bird | PRUNUS PADUS |
| Cherry, Wild | PRUNUS AVIUM |
| Charlock | SINAPIS ALBA |
| Chicory | CICHORIUM INTYBUS |
| Cleavers, Sweethearts, Sticky-Willy | GALIUM APARINE |
| Clover, Red | TRIFOLIUM PRATENSE |
| Clover, White | TRIPOLIUM REPENS |
| Coltsfoot | TUSIILAGO FARFARA |
| Common Comfrey | SYMPHYTUM OFFICINALE |
| Common Fumitory | FUMARIA OFFICINALIS |
| Common Knapweed | CENTAUREA NIGRA |
| Common Sorrel | RUMEX ACETOSA |
| Corn Chamomile | ANTHEMIS ARVENSIS |
| Corncockle | AGROSTEMMA GITHAGO |
| Cornflower | CENTAUREA CYANUS |
| Corn marigold | CHRYSANTHEMUM SEGETUM |
| Cow-parsley | ANTHRISCUS SYLVESTRIS |
| Cowslip | PRIMULA VERIS |
| Creeping Jenny | LYSIMACHIA NUMMULARIA |
| Cuckoo Flower, Lady's Smock, Milkmaids. | CARDAMINE PRATENSIS |