Cicerbita Cigar Flower (spp.)
Cigar Plant (spp.) Cigar Plant, Tall
Cineraria, Florist's (spp.) Cineraria, Florist's 'Cornflower Blue'
'Cinnamon Bear' Foamy Bells Cinnamon Cactus
Cinquefoil, Creeping Cinquefoil, Five Finger
Cinquefoil, Nepal 'Ron McBeath' Cinquefoil, Spring
Cinquefoil, Woolly Cinquefoil: megalantha
Cinquefoil: nepalensis 'Ron McBeath' Cinquefoil: tongueihybrid
'Cirrus' Dusty Miller: cineraria 'Cisty Joiner' Daylily
'Citronella' Dog's Tooth Violet 'Citronella' Spanish Flag
'Citrus' Lemon-Scented Thyme 'Clairette' Dwarf Iris
'Clara Curtis' Korean Chrysanthemum 'Clarence Simon' Daylily
'Clarence' Tall Bearded German Iris Clarke's Geranium 'Kashmir Purple'
'Clarks Red' Common Sugarbush Clary Sage (spp.)
'Claude Barre' Penstemon Clavelina Cactus
Clematis (spp.) Clematis 'Alexander'
Clematis, Blue (spp.) Clematis, Blue 'Hanajina'
Clematis, Blue 'Rosea' Clematis, Evergreen (spp.)
Clematis, Fall Clematis, Ground 'Purpurea'
Clematis, Hybrid (spp.) Clematis, Hybrid 'Asao'
Clematis, Hybrid 'Blue Angel (Blekitny Aniol)' Clematis, Hybrid 'Cardinal Wyszynski'
Clematis, Hybrid 'Carnaby' Clematis, Hybrid 'Dorota'
Clematis, Hybrid 'Guernsey Cream' Clematis, Hybrid 'John Paul II'
Clematis, Hybrid 'Mme Le Coultre' Clematis, Hybrid 'Montana Rubens'
Clematis, Hybrid 'Mrs. N. Thompson' Clematis, Hybrid 'Multi Blue'
Clematis, Hybrid 'Pink Fantasy' Clematis, Hybrid 'Ramona'
Clematis, Hybrid 'Sho-Un' Clematis, Hybrid 'Silver Moon'
Clematis, Hybrid 'Snow Queen' Clematis, Hybrid 'Sunset'
Clematis, Hybrid 'Sweet Summer Love' Clematis, Hybrid 'Vyvyan Pennell'
Clematis, Hybrid 'Warsaw Nike' Clematis, Hybrid 'Will Goodwin'
Clematis, Jackman (spp.) Clematis, Jackman 'Purpurea Superba'
Clematis, Large Petal 'Markham's Pink' Clematis, Scarlet 'Duchess of Albany'
Clematis, Sweet Autumn Clematis, Texas 'Duchess of Albany'
Clematis, Tube 'Alan Bloom' Clematis: (n) 'Jackmanii'
Clematis: lanuginosa 'Red Cardinal' Clematis: montana rubens
Clematis: ochroleuca Clematis: tangutica (spp.)
Clematis: tangutica 'Helios' Clematis: terniflora, Sweet Autumn
'Cleo' Daylily 'Cleopatra' Scarlet Sage: splendens
'Cleveland Morgan' Hen and Chickens 'Clevelandii' Peace Lily
Cliff Brake Fern Cliff Maids (spp.)
Cliff Maids 'Ashwood Strain' Cliff Maids 'Hybrid Mix'
Climbing Aloe Climbing Bleeding Heart (spp.)
Climbing Bleeding Heart 'Athen's Yellow' Climbing Hemp Vine
Climbing Hempweed Climbing Knotweed
Climbing Nightshade Climbing Snapdragon (spp.)
Climbing Snapdragon 'Jewels' Clintonia, White
Clivia, Yellow-flowered Clock Vine
Clock Vine, Orange Closed Gentian