Colchicum autumnale
Meadow Saffron
Comarum palustre
Marsh Cinquefoil
Commelina diffusa
Climbing Dayflower
Conium maculatum
Hemlock
Conocarpus erectus
Buttonwood
Conopodium majus
Pignut
Convallaria majalis
Lily-of-the-valley
Convolvulus arvensis
Field Bindweed
Cordyline fruticosa
Ti Plant
Cornus capitata
Bentham's Dogwood
Cornus sanguinea
Dogwood
Corylus avellana
Hazel
Cotoneaster cambricus
Wild Cotoneaster
Cotoneaster horizontalis
Wall Cotoneaster
Cotoneaster melanocarpus
Cotoneaster tomentosus
Cotoneaster (tomentosus)
Couroupita guianensis
Cannonball tree
Crassula helmsii
New Zealand Pigmyweed
Crataegus laevigata
Midland Hawthorn
Crepis capillaris
Smooth Hawk's-beard
Cruciata laevipes
Crosswort
Cryptogramma crispa
Parsley Fern
Cryptomeria japonica
Japanese Red-cedar
Cupressus nootkatensis
Nootka Cypress