- chamaephyte
- chasmogamy
- chervile
- chile pine
- chinkapin
- chokeberry
- cion
- chlorenchyma
- cladode
- cladophyll
- club-nodding
- club-stalked
- colocynth
- collenchyma
- coleoptile
- coleus
- comospore
- conidial
- conidiophore
- conidium
- connocarpus
- consperse
- copaliferous
- coprophyte
- coquilla nut
- cork-cambium
- corollaceou
- corymbiferous
- courgette
- costa
- cotton-wood
- courbaril
- cow-flap
- cranesbill
- crape-myrtle
- crapper
- cowpea
- crassula
- cremocarp
- crowdfoot
- cudbear
- croton
- crow-berry
- crowfoot
- crown imperial
- cushaw
- cryptocarp
- cryptomeria
- cubeb
- cucullate
- cucullus
- cucumis
- cudweed
- cyanophyte
- cystocarp
- decurrence
- decapitated
- dasheen
- dayflower
- decandrous
- diad
- diageotropic
- dictyogen
- disseminule
- dogbane
- dorsiferous
- dorsifixed
- dropwort
- dulse
- durum
- echinocactus
- echinocarp
- emarginate
- emersed
- end-bud
- endarch
- endogen
- entomochoric
- endostone
- endothecium
- enervose
- enphytotic
- entophyte
- epicalyx
- epichilium
- epicotyl
- epigyne
- epigyny
- epinasty
- epinytic
- epiperidium
- epipetalous
- epiphyll
- embryosac
- enantioblastic
- endodermis
- epibole
- escarole
- eucarpic
- eugenia