Cortaderia selloana Cortaderia selloana 'Aureolineata'
Cortaderia selloana 'Aureo-Picta' Cortaderia selloana 'Pumila'
Cortaderia selloana 'Silver Comet' Cortaderia selloana 'White'
Cortaderia toetoe Corydalis aurea
Corydalis elata 'Rhythm 'n' Blues' Corydalis flexuosa 'Blue Panda'
Corydalis flexuosa 'China Blue' Corydalis flexuosa 'Purple Leaf'
Corydalis lutea Corydalis lutea 'Alba'
Corydalis micrantha Corydalis ochroleuca
Corynephorus canescens 'Spiky Blue' Coryphantha elephantidens
Coryphantha erecta Cosmos atrosanguineus
Cosmos bipinnatus Cosmos bipinnatus 'Early Wonder'
Cosmos bipinnatus 'Sonata White' Cosmos sulphureus
Cosmos sulphureus 'Cosmic Orange' Cosmos sulphureus 'Cosmic Red'
Cosmos sulphureus 'Cosmic Yellow' Cosmos sulphureus 'Ladybird Scarlet'
Cosmos sulphureus 'Lemon Twist' Cosmos sulphureus 'Sunny Red'
Costus barbatus Costus comosus
Costus curvibracteatus Costus cuspidatus
Costus malortieanus Costus pictus
Costus pulverulentus Costus speciosus
Costus speciosus 'Nova' Costus speciosus 'Variegatus'
Costus varzearum Costus woodsonii
Cotula coronopifolia Cotyledon orbiculata
Crambe cordifolia Crassula arborescens
Crassula capitella 'Campfire' Crassula muscosa
Crassula muscosa pseudolycopodiodes 'Princess Pine' Crassula ovata
Crassula ovata 'Pink Beauty' Crassula ovata 'Tricolor'
Crassula ovata 'Variegata' Crassula perfoliata var. falcata
Crassula pubescens radicans Crinum amabile
Crinum americanum Crinum asiaticum 'Cuprifolium'
Crinum asiaticum var. procerum Crinum asiaticum var. sinicum
Crinum bulbispermum Crinum moorei
Crinum x powellii Crinum x powellii 'Ellen Bosanquet'
Crinum spp. Crithmum maritimum
Crocosmia x crocosmiiflora Crocosmia x crocosmiiflora 'Emily McKenzie'
Crocosmia x crocosmiiflora 'George Davidson' Crocosmia x crocosmiiflora 'Lucifer'
Crocosmia x crocosmiiflora 'Norwich Canary' Crocosmia x crocosmiiflora 'Wallerton Red'
Crocosmia masonorum Crocus 'Violet Queen'
Crocus chrysanthus 'Advance' Crocus goulimyi
Crocus x hybridus Crocus pulchellus
Crocus sativus Crocus speciosus
Crocus tommasinianus Crocus tommasinianus 'Barr's Purple'
Crocus vernus ssp. vernus 'Jeanne d'Arc' Crossandra infundibuliformis
Crossandra infundibuliformis 'Florida Summer' Crossandra spp.
Cryptanthus bivittatus Cryptotaenia japonica 'Atropurpurea'
Ctenanthe oppenheimiana 'Tricolor' Cucumis melo
Cucumis melo 'Angel' Cucumis sativus 'Diva'
Cucurbita 'Cornell's' Cucurbita 'Papaya Pear'
Cucurbita pepo 'Butterstick' Cucurbita pepo 'Orange Smoothie'
Cucurbita pepo 'Sorcerer' Cucurbita pepo 'Sunshine'