| Centaurea nigra |
|
| Centaurium pulchellum |
Lesser Centuary |
| Cerastium fontanum |
Common Mouse-Ear |
| Cerastium glomeratum |
Clammy Chickweed; Sticky Mouse-Ear |
| Cerastium holosteoides |
Big Chickweed; Common Mouse-Ear |
| Cerastium tomentosum |
Snow in Summer |
| Chamaenerion angustifolium angustifolium |
Fireweed; Rosebay Willowherb |
| Cheilymenia fimicola |
|
| Chenopodium album |
Pigweed; Fat Hen; Goosefoots |
| Cichorium intybus |
Chicory |
| Cirsium arvense |
Creeping Thistle; Californian Thistle |
| Cirsium arvense arvense |
Creeping Thistle |
| Claviceps purpurea |
|
| Claytonia perfoliata |
Winter Purslane; Spring Beauty |
| Claytonia perfoliata perfoliata |
Miner's-Lettuce; |
| Clitocybe amarescens |
|
| Clitocybe vibecina |
|
| Cochlearia officinalis |
English Scurvygrass |
| Conium maculatum |
Poison Hemlock; Hemlock |
| Conocybe pubescens |
|
| Coprinopsis nivea |
|
| Cordyline australis |
Cabbage Palm |
| Cortaderia jubata |
Pampas Grass |
| Cotoneaster suecicus |
Cotoneaster |
| Crataegus monogyna |
Oneseed Hawthorn; Hawthorn |
| Crepis capillaris |
Smooth Hawks-Beard |
| Crocus vernus |
|
| Cymbalaria muralis |
Ivy-Leaved Toadflax |
| Cynosurus cristatus |
Crested Dogs Tail |
| Cynosurus echinatus |
Rough Dogs Tail |
