| C |
| Caladium, Caladium, Elephant's ear, Angel wings |
| Calamagrostis brachytricha (Calamagrostis arundinacea var. brachytricha), Korean feather reed grass |
| Calamagrostis x acutiflora 'Karl Foerster', Karl Foerster: feather reed grass |
| Calamagrostis x acutiflora, Feather reed grass |
| Calendula officinilalis, Calendula; Pot marigold |
| Callicarpa americana, American beautyberry |
| Callistephus chinensis, China aster |
| Calocedrus decurrens, Incense ceder; California incense cedar |
| Calochortus, Butterfly tulip, Mariposa lily, Globe tulip, Star tulip |
| Calonyction aculeatum, Ipomea alba, Moonflower, Moonvine |
| Caltha palustris, Marsh marigold |
| Calycanthus floridus, Sweet shrub; Sweet Betsy, Carolina allspice |
|
Camassia cusickii, C. esculenta,Indian Quamash, Camass, Wild Hyacinth |
| Camassia, Quamash, Wild hyacinth, Camas |
|
Campanula spp., Bellflower |
| Campanula americana, Bellflower |
| Campsis grandiflora, Trumpet vine, Chinese trumpet creeper |
| Campsis radicans, Trumpet creeper, Trumpet vine |
| Campsis x tagliabuana, Trumpet creeper, Madame Galen |
| Canna, Canna, Indian shot, Arrowroot |
| Cardiocrinum, Giant Lily, Easter Lily |
| Carduus muticus, Thistle, Swamp thistle |
| Carex albula 'Frosty Curls', Frosty Curls sedge |
| Carex conica , Hime kan suga |
| Carex dolichostachya 'Kaga Nishiki', Gold fountains, Kaga brocade sedge |
| Carex elata (Carex stricta), Tufted grass, tufted sedge |
| Carex firma (Carex glauca), Glaucous sedge, carnation grass |
| Carex morrowii var. temnolepsis (Carex temnolepis), Hosoba kan suge |
| Carex morrowii, Marrow's sedge, Japanese sedge |
| Carex muskingumensis, Palm sedge |
| Carex oshimensis 'Evergold', Evergold striped weeping sedge, Oshima kan suge |
| Carex phyllocephala, Tenjiku suge |
| Carex siderosticha , Creeping broad leafed sedge |
| Carex spp., Carex |
| Carpinus betulus, European hornbeam; Musclewood; Ironwood |
| Carpinus caroliniana, Ironwood; Musclewood; Amwerican hornbeam |
| Carpinus cordata, Heartleaf hornbeam |
| Carpinus japonica, Japanese hornbeam |
| Carpinus orientalis, Oriental hornbeam |
| Carum carvi, Caraway |
| Carya cordiformis, Bitternut hickory |
| Carya glabra, Pignut hickory |
| Carya illinoinensis, Pecan |
| Carya myristicaeformis, Nutmeg hickory |
| Carya ovalis,Red hickory |
| Carya ovata, Shagbark hickory |
| Carya pallida,Sand hickory |
| Carya tomentosa, Mocknut hickory; White hickory |
|
Caryopteris spp., Bluebeard |
| Cassia fasciculata (Chamaecrista fasciculata), Partridge pea, Senna |
| Castanea dentata, American chestnut |
| Castanea pumila, Chinquapin |
| Castanea sative, Spanish chestnut |
| Castilleja coccinea, Indian paintbrush |
| Catalpa bignonioides, Southern catalpa |
| Catalpa speciosa, Northern catalpa |
| Catalpa spp.,Catalpa |
| Catharanthus roseus, Vinca, Madagascar periwinkle |
| Ceanothus americanus, New Jersey tea; Mountain snowbell |
| Cedrela sinsensis = Toona sinensis, Chinese toon; Chinese cedrela |
| Cedrus atlantica 'Glauca', Blue Atlas cedar |
| Cedrus atlantica, Atlas cedar |
| Cedrus deodara, Deodar cedar |
| Cedrus libani, Cedar of Lebanon |
| Celastrus orbiculatus, Chinese bittersweet |
| Celastrus orbiculatus, Oriental bittersweet |
| Celastrus scandens, American bittersweet |
| Celastrus scandens, Climbing bittersweet; American bittersweet |
| Celosia crista, Cockscomb; Celosia |
| Celtis laevigata, Hackberry; Sugarberry |
| Celtis laevigata,Sugarberry |
|
Centaurea montana, Mountain bluet |
| Centaurea cineraria, Dusty miller |
| Centaurea cyanus, Bachelor's button |
|
Centranthus ruber, Red valerian |
| Cephalanthus occidentalis, Buttonbush |
| Ceratiola ericoides, Sandhill rosemary |
|
Ceratostigma plumbaginoides, Leadwort |
| Cercidiphyllum japonicium, Katsura tree |
| Cercis californica ssp. californica, Western red bud; California redbud |
| Cercis canadensis ssp. mexicana, Mexican redbud |
| Cercis canadensis ssp. retisus, Oklahoma redbud |
| Cercis canadensis ssp. texensis, Texas redbud |
| Cercis canadensis, Eastern redbud |
| Cercis chinensis, Chinese redbud |
| Cercis chingii, Redbud |
| Cercis giganteta, Giant redbud |
| Cercis racemosa, Chain flowered redbud |
| Cercis siliquastrum, Mediterranean redbud |
| Cercis yunnanensis, Yunnan redbud |
| Chamaecypari obtusa, Hinoki falsecypress |
| Chamaecyparis pisifera, Japanese falsecypress; Sawara falsecypress |
| Chamaecyparis thyoides, Atlantic whitecedar |
| Chamaemelum nobile, Chamomile |
| Chasmanthe, Pennants |
| Chasmanthium latifolium, Wild oats, Northern sea oats |
| Chelone lyonii, Turtlehead |
| Chionanthus retusus, Chinese fringetree |
| Chionanthus virginicus, Fringe tree; Oldman's beard |
|
Chionodoxa luciliae, C. gigantea,Glory of the Snow |
| Chlidanthus fragrans, Perfumed fairy lily, Delicate lily |
|
Chrysanthemum morifolium, Chrysanthemum |
|
Chrysanthemum x superbum, Shasta daisy |
| Chrysanthemum balsamita, Costmary |
| Chrysanthemum leucanthemum, Ox-eye daisy |
| Chrysogonum virginianum, Green and gold |
| Cichorium intybus, Chicory |
| Cimicifuga racemosa, Black cohosh |
| Cladrastis lutea, Yellowwood |
| Claytonia caroliniana, Spring beauty |
| Clematis armandii, Armand clematis |
| Clematis coccinea, Clematis texensis, Scarlet clematis |
| Clematis hybrida,Clematis, Hybrids |
| Clematis maximonowicziana, Clematis paniculata, Sweet autumn clematis |
| Clematis montana, Anemone clematis, Indian's virgin's bower |
| Clematis paniculata, Clematis. maximonowicziana, Sweet autumn clematis |
| Clematis spp., Clematis, Leather flower; Virgin's bower |
| Clematis texensis, C. coccinea, Scarlet clematis |
| Clematis viorma, Leather flower |
| Clematis virginiana, Virgin's Bower clematis |
| Clematis viticella, Italian clematis |
| Clematis x jackmanii, Jackman clematis |
| Cleome hasslerana, Cleome; Spider flower |
| Clerodendrum trichotomum, Harlequin glorybower |
| Clethra acuminata, Cinnamonbark clethra; Mountain pepperbush |
| Clethra alnifolia, Summersweet, Sweet pepperbush; Clethra |
| Cliftonia monophylla, Buckwheat tree |
| Clitoria mariana, Butterfly pea |
|
Clivia miniata,Kaffir Lily, Flame Lily, September Lily |
| Clivia, Kaffir lily, Flame lily, Bush lily |
| Cobaena scandens, Cup-and-saucer vine, Coral bells, Cathedral bells, Mexican ivy, Monastery bells |
| Cocculus carolina, Carolina moonseed; Coral-beads |
| Coix lacryma-jobi, Job's tears |
| Colchicum autumnale, Autumn crocus, Wonder bulb, Mysteria |
| Coleus x hybridus, Coleus |
| Colocasia, Elephant's ear, Taro, Dasheen |
| Commelina communis, Dayflower |
| Conopholis americana, Squaw root; Cancer corn |
| Conradina verticillata, Cumberland rosemary |
|
Convallaria majalis,Lily of the Valley |
|
Coreopsis lanceolata, Lanceleaf coreopsis |
|
Coreopsis verticillata, Threadleaf coreopsis |
| Coreopsis spp., Coreopsis |
| Coriandrum sativum, Coriander (cilantro) |
| Cornus alternifolia, Alternateleaved dogwood; Pagoda dogwood |
| Cornus amomum, Silky dogwood |
| Cornus asperifolia,Roughleaf dogwood |
| Cornus controversa, Giant dogwood |
| Cornus florida, Flowering dogwood |
| Cornus hybrids, Dogwood, Stellar hybrids |
| Cornus kousa, Kousa dogwood |
| Cornus mas, Cornelainche rry dogwood |
| Cornus officinalis, Japanese cornel dogwood |
| Cornus sanguinea, Bloodtwig dogwood |
| Cornus stricta,Swamp dogwood |
| Cortaderia selloana, Pampas grass |
| Corylorsis glabrescens, Fragrant winterhazel |
| Corylus avellana, European filbert |
| Cosmos spp., Cosmos |
| Cotinus coggygria, Smoketree |
| Cotoneaster dammeri, Bearberry cotoneaster |
| Cotoneaster horizontalis, Rockspray cotoneaster |
| Cotoneaster salicifolius 'Repens', Willowleaf cotoneaster |
| Crataegus crusgallii, Cockspur hawthorn |
| Crataegus mollis, Down hawthorne |
| Crataegus oxycantha = C. laevigata, English hawthorne |
| Crataegus phaenopyrum, Washington hawthorn |
| Crataegus pinnatifida, Crataegus |
| Crataegus spp.,Hawthorn |
| Crataegus x lavalleri, Carriere hawthorn; Lavallei |
| Crategus virdis 'Winter King', Washington hawthorn |
| Crinum, Crinum, Cape lily, Spider lily, Swamp lily |
|
Crocosmia hybrids, Coppertip, Falling Stars |
| Crocosmia = Montbretia, Crocosmia, Coppertip, Falling stars |
|
Crocus spp. (Spring flowering), Dutch Crocus, Species Crocuses |
| Crocus (Autumn Species), Fall crocus |
| Cryptomeria japonica, Japanese cryptomeria; Japanese cedar |
| Cunninghamia lanceolata, China fir |
| Cuphea hyssopifolia, Mexican heather |
| Cupressus sempervirens, Italian cypress |
| Curcuma, Turmeric |
| Curtonus, Pleated leaves |
| Cyclamen, Snowbread, Persian violet, Alpine violet |
| Cydonia sinensis = Pseudocydonia sisensis, Chinese quince |
| Cymbopogon citratus, Lemon grass |
| Cypripedium spp., Lady slipper, Lady's-slipper, Moccasin flower |
| Cyressus arizonica, Arizona cypress |
| Cyrilla racemiflora, Titi, Leatherwood |
| Cyrtanthus = Vallota, Fire lily, Scarborough lily, George lily |
|
x Crinodonna corsii,Crinodonna |
| x Crinodonna, A hybrid Crinum x A. belladonna |