Castorbean _Ricinus_ 51 Catalpa _Catalpa_ 56 Catchfly, sleepy _Silene antirrhina_ 52 Catchflygrass _Leersia lenticularis_ 22 Catnip _Nepeta cataria_ 48 Cattail _Typha_ 30 Ceanothus _Ceanothus_ 56 Centaurea _Centaurea_ 38 Centipedegrass _Eremochloa_ 21 Cerastium _Cerastium_ 38 Charlock _Brassica kaber_ 38 Cheat _Bromus secalinus_ 20 Cherry _Prunus_ 57 Chervil _Chaerophyllum_ 38 Chickencorn _Sorghum bicolor_ var. _drummondii_ 25 Chickpea _Cicer_ 31 Chickweed _Stellaria media_ 54 Chicory _Cichorium_ 39 Chineselantern _Physalis lobata_ 50 Chloris _Chloris_ 20 Chokecherry _Prunus virginiana_ 57 Cholla _Opuntia_ 48 Christmasfern _Polystichum acrostichoides_ 29 Cinquefoil _Potentilla_ 51 Circaea _Circaea_ 39 Clammyweed _Polanisia_ 50 Clearweed _Pilea_ 50 Clematis _Clematis_ 39 Cleomella _Cleomella_ 39 Cliffbrake _Pellaea_ 28 Climbing-buckwheat _Polygonum convolvulus_ 50 Climbingmilkweed _Ampelamus albidus_ 35 Cloakfern _Notholaena_ 28 Clover _Trifolium_ 34 Cockle, white _Lychnis alba_ 47 Cocklebur _Xanthium_ 55 Cockspur _Echinochloa_ 21 Coffeetree _Gymnocladus_ 32, 57 Cogongrass _Imperata_ 22 Collinsia _Collinsia_ 39 Columbine _Aquilegia_ 36 Comandra _Comandra_ 39