Cabbage          

Cactus Apple          

Caespitose Four-nerve Daisy          

Cainville Thistle          

Calcareous Cryptantha          

Caley Pea      

Calibrachoa          

Caliche Globemallow          

California Brickellbush          

California Buckthorn          

California Bulrush      

California Caltrop          

California Cottonrose          

California False Hellebore      

California Goldfields          

California Loosestrife          

California Mustard          

California Nettle          

California Oatgrass      

California Poppy      

California Satintail          

California Tickseed          

Caltrop          

Calyptocarpus          

Camelthorn          

Camphorweed          

Canada Bluegrass      

Canada Cocklebur          

Canada Germander      

Canada Goldenrod          

Canada Lettuce          

Canada Thistle          

Canada Wildrye      

Canadian Anemone          

Canadian Horseweed      

Canadian Lousewort      

Canadian Milkvetch      

Canadian Waterweed      

Canadian White Violet          

Canaigre Dock          

Canarygrass          

Cancer-root          

Candelilla          

Candle Anemone