Cleome hassleriana Cleome hassleriana 'Helen Campbell'
Cleome hassleriana 'Linde Armstrong' Cleome hassleriana 'Purple Queen'
Cleome hassleriana 'Sparkler Mix' Cleome hassleriana 'White Queen'
Clerodendranthus spicatus Clerodendrum thomsoniae
Clintonia andrewsiana Clintonia umbellulata
Clitoria ternatea Clivia miniata
Clivia miniata var. citrina Clivia miniata var. citrina 'Variegata'
Cobaea scandens Codonopsis 'Lilac Eyes'
Coelogyne x 'Burfordiense' Coix lacryma-jobi
Colchicum autumnale Colchicum autumnale 'Waterlily'
Colchicum speciosum Colchicum speciosum 'The Giant'
Coleocephalocereus goebelianus Colocasia esculenta
Colocasia esculenta 'Black Magic' Colocasia esculenta 'Fontanesii'
Colocasia esculenta 'Hawaiian® Black Coral' Colocasia esculenta 'Illustris'
Colocasia esculenta 'Milky Way' Colocasia esculenta 'Mojito'
Colocasia esculenta 'Nancy's Revenge' Colocasia esculenta 'Tea Cup'
Colocasia gigantea 'Thailand Giant Strain' Colquhounia coccinea
Columnea gloriosa Columnea schiedeana
Commelina coelestis Conicosia pugioniformis
Conicosia pugioniformis ssp. muirii Conium maculatum
Conoclinium coelestinum Conoclinium greggii
Conostylis seorsiflora Consolida ambigua
Convallaria majalis Convallaria majalis 'Aureo-variegata'
Convallaria majalis 'Striata' Convolvulus althaeoides ssp. tenuissimus
Convolvulus cneorum Convolvulus sabatius
Convolvulus tricolor Convolvulus tricolor 'Royal Ensign'
Cordyline australis Cordyline australis 'Purple Tower'
Cordyline australis 'Sundance' Cordyline banksii 'Sprilecpink (Electric Pink)'
Cordyline obtecta Cordyline terminalis
Cordyline terminalis 'Dr. Brown' Cordyline terminalis 'Exotica'
Coreopsis 'Creme Brule' Coreopsis 'Experimental Coreopsis COR118'
Coreopsis 'Limerock Dream' Coreopsis 'Limerock Passion'
Coreopsis 'Limerock Ruby' Coreopsis 'Tequila Sunrise'
Coreopsis auriculata Coreopsis auriculata 'Nana'
Coreopsis auriculata 'Zamphir' Coreopsis x delphinifolia 'Blue Mirror'
Coreopsis gigantea Coreopsis grandiflora 'Early Sunrise'
Coreopsis grandiflora 'Heliot' Coreopsis grandiflora 'Sunray'
Coreopsis grandiflora 'Walcoreop(Flying Saucers ™)' Coreopsis integrifolia
Coreopsis lanceolata Coreopsis lanceolata 'Baby Sun'
Coreopsis lanceolata 'Goldfink' Coreopsis lanceolata 'Sterntaler'
Coreopsis rosea Coreopsis rosea 'Alba'
Coreopsis rosea 'American Dream' Coreopsis rosea 'Sweet Dreams'
Coreopsis tinctoria Coreopsis tinctoria 'Mahogany Midget'
Coreopsis tinctoria 'Mardi Gras' Coreopsis verticillata 'Golden Gain'
Coreopsis verticillata 'Golden Showers' Coreopsis verticillata 'Grandiflora'
Coreopsis verticillata 'Moonbeam' Coreopsis verticillata 'Zagreb'
Cornukaempferia aurantiflora 'Jungle Gold' Cornus canadensis