| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| CONI4 | Commelina nigritana Benth. | African dayflower | Commelinaceae
|
| CONU7 | Commelina nudiflora L. | Murdannia nudiflora | Commelinaceae
|
| CORUG | Commelina rufipes Seubert var. glabrata (D. Hunt) Faden & D.R. Hunt | cojite blanco | Commelinaceae
|
| CORU6 | Commelina rufipes Seubert | cojite blanco | Commelinaceae
|
| COSA3 | Commelina saxicola Small | Commelina erecta var. erecta | Commelinaceae
|
| COSE12 | Commelina serrulata Vahl | Tripogandra serrulata | Commelinaceae
|
| COSP5 | Commelina spirata L. | Murdannia spirata | Commelinaceae
|
| COTU5 | Commelina tuberosa L. | commelina | Commelinaceae
|
| COVI3 | Commelina virginica L. | Virginia dayflower | Commelinaceae
|
| COWI4 | Commelina willdenowii Kunth | Commelina communis var. communis | Commelinaceae
|
| COZA | Commelina zanonia L. | Tradescantia zanonia | Commelinaceae
|
| COMME | Commelina L. | dayflower | Commelinaceae
|
| COAN12 | Commelinantia anomala (Torr.) Tharp | Tinantia anomala | Commelinaceae
|
| COPE6 | Commelinopsis persicariifolia (Delile) M. Pichon | Commelina rufipes var. glabrata | Commelinaceae
|
| COSC | Commicarpus scandens (L.) Standl. | Boerhavia scandens | Nyctaginaceae
|
| COHA4 | Commiphora habessinica (Berg) Engler | Abyssinian myrrh | Burseraceae
|
| COOP2 | Commiphora opobalsamum (L.) Engler | Mecca myrrh | Burseraceae
|
| COMMI2 | Commiphora Jacq. | myrrh | Burseraceae
|
| CODO | Comocladia dodonaea (L.) Urban | poison ash | Anacardiaceae
|
| COGL4 | Comocladia glabra (J.A. Schultes) Spreng. | carrasco | Anacardiaceae
|
| COMOC | Comocladia P. Br. | maidenplum | Anacardiaceae
|
| COFA2 | Comparettia falcata Poepp. & Endl. | snail orchid | Orchidaceae
|
| COMPA | Comparettia Poepp. & Endl. | comparettia | Orchidaceae
|
| COGR18 | Complaya gracilis (L.C. Rich.) Strother | Sphagneticola gracilis | Asteraceae
|
| COTR14 | Complaya trilobata (L.) Strother | Sphagneticola trilobata | Asteraceae
|
| COPEA | Comptonia peregrina (L.) Coult. var. aspleniifolia (L.) Fern. | Comptonia peregrina | Myricaceae
|
| COPE80 | Comptonia peregrina (L.) Coult. | sweet fern | Myricaceae
|
| COMPT | Comptonia L'H�r. ex Ait. | sweet fern | Myricaceae
|
| COPO4 | Conami portoricensis (Kuntze) Britt. | Flueggea acidoton | Euphorbiaceae
|
| COCO31 | Conardia compacta (C. M�ll.) Robins. | compact conardia moss | Amblystegiaceae
|
| CONAR | Conardia Robins. | conardia moss | Amblystegiaceae
|
| COCO11 | Condalia correllii M.C. Johnston | Correll's snakewood | Rhamnaceae
|
| COER5 | Condalia ericoides (Gray) M.C. Johnston | javelin bush | Rhamnaceae
|
| COGLP | Condalia globosa I.M. Johnston var. pubescens I.M. Johnston | bitter snakewood | Rhamnaceae
|
| COGL | Condalia globosa I.M. Johnston | bitter snakewood | Rhamnaceae
|
| COHOE | Condalia hookeri M.C. Johnston var. edwardsiana (Cory) M.C. Johnston | Edwards' bluewood | Rhamnaceae
|
| COHOH | Condalia hookeri M.C. Johnston var. hookeri | Brazilian bluewood | Rhamnaceae
|
| COHO | Condalia hookeri M.C. Johnston | Brazilian bluewood | Rhamnaceae
|
| COLYC | Condalia lycioides (Gray) Weberb. var. canescens (Gray) Trel. | Ziziphus obtusifolia var. canescens | Rhamnaceae
|
| COLY2 | Condalia lycioides (Gray) Weberb. | Ziziphus obtusifolia var. obtusifolia | Rhamnaceae
|
| COOB7 | Condalia obovata Hook. | Condalia hookeri var. hookeri | Rhamnaceae
|
| COOB6 | Condalia obtusifolia (Hook. ex Torr. & Gray) Weberb. | Ziziphus obtusifolia var. obtusifolia | Rhamnaceae
|
| COPA27 | Condalia parryi (Torr.) Weberb. | Ziziphus parryi | Rhamnaceae
|
| COSP3 | Condalia spathulata Gray | knifeleaf condalia | Rhamnaceae
|
| COVI8 | Condalia viridis I.M. Johnston | green snakewood | Rhamnaceae
|
| COWAK | Condalia warnockii M.C. Johnston var. kearneyana M.C. Johnston | Kearney's snakewood | Rhamnaceae
|
| COWAW | Condalia warnockii M.C. Johnston var. warnockii | Warnock's snakewood | Rhamnaceae
|
| COWA | Condalia warnockii M.C. Johnston | Warnock's snakewood | Rhamnaceae
|
| CONDA | Condalia Cav. | snakewood | Rhamnaceae
|
| COLYC2 | Condaliopsis lycioides (Gray) Suess. var. canescens (Gray) Suess. | Ziziphus obtusifolia var. canescens | Rhamnaceae
|
| COLY3 | Condaliopsis lycioides (Gray) Suess. | Ziziphus obtusifolia var. obtusifolia | Rhamnaceae
|
| COPA21 | Condaliopsis parryi (Torr.) Suess. | Ziziphus parryi | Rhamnaceae
|
| COIR | Condylidium iresinoides (Kunth) King & H.E. Robins. | villalba | Asteraceae
|
| CONDY2 | Condylidium King & H.E. Robins. | villalba | Asteraceae
|
| COTO2 | Congea tomentosa Roxb. | lluvia de orquideas | Verbenaceae
|
| CONGE | Congea Roxb. | congea | Verbenaceae
|
| COPU18 | Conicosia pugioniformis (L.) N.E. Br. | narrow-leaved iceplant | Aizoaceae
|
| CONIC | Conicosia N.R. Br. | narrow-leaved iceplant | Aizoaceae
|
| COWI | Conimitella williamsii (D.C. Eat.) Rydb. | Williams' miterwort | Saxifragaceae
|
| CONIM | Conimitella Rydb. | conimitella | Saxifragaceae
|
| COFU6 | Coniocybe furfuracea (L.) Ach. | Chaenotheca furfuracea | Coniocybaceae
|
| COGR15 | Coniocybe gracilescens Willey | pin lichen | Coniocybaceae
|
| COGR17 | Coniocybe gracillima Vainio | Chaenotheca gracillima | Coniocybaceae
|
| CONI9 | Coniocybe nivea (Hoffm.) Arnold | Sclerophora nivea | Coniocybaceae
|
| COPA31 | Coniocybe pallida (Pers.) Fr. | Sclerophora nivea | Coniocybaceae
|
| COSU16 | Coniocybe sulphurea (Retz.) Nyl. | Chaenotheca brachypoda | Coniocybaceae
|
| CONIO3 | Coniocybe Ach. | pin lichen | Coniocybaceae
|
| COAR13 | Coniocybopsis arenaria (Hampe ex A. Massal.) Vainio | Microcalicium arenarium | Microcaliciaceae
|
| COPI3 | Coniogramme pilosa (Brack.) Hieron. | loulu | Pteridaceae
|
| CONIO2 | Coniogramme F�e | coniogramme | Pteridaceae
|
| COCHP | Conioselinum chinense (L.) B.S.P. var. pacificum (S. Wats.) Boivin | Conioselinum gmelinii | Apiaceae
|
| COCH2 | Conioselinum chinense (L.) B.S.P. | Chinese hemlockparsley | Apiaceae
|
| COCN | Conioselinum cnidiifolium (Turcz.) Porsild | Cnidium cnidiifolium | Apiaceae
|
| COGM | Conioselinum gmelinii (Cham. & Schlecht.) Steud. | Pacific hemlockparsley | Apiaceae
|
| COME2 | Conioselinum mexicanum Coult. & Rose | Mexican hemlockparsley | Apiaceae
|
| COPA22 | Conioselinum pacificum (S. Wats.) Coult. & Rose | Conioselinum gmelinii | Apiaceae
|
| COPU14 | Conioselinum pumilum Rose | Conioselinum chinense | Apiaceae
|
| COSC2 | Conioselinum scopulorum (Gray) Coult. & Rose | Rocky Mountain hemlockparsley | Apiaceae
|
| CONIO | Conioselinum Hoffmann | hemlockparsley | Apiaceae
|
| COMA2 | Conium maculatum L. | poison hemlock | Apiaceae
|
| CONIU | Conium L. | poison hemlock | Apiaceae
|
| COSEG | Connarus semidecandrus Jack var. gaudichaudii (DC.) F.R. Fosberg | | Connaraceae
|
| COSE19 | Connarus semidecandrus Jack | | Connaraceae
|
| CONNA | Connarus L. | | Connaraceae
|
| COMU4 | Conobea multifida (Michx.) Benth. | Leucospora multifida | Scrophulariaceae
|
| COERS | Conocarpus erectus L. var. sericeus Fors ex DC. | Conocarpus erectus | Combretaceae
|
| COER2 | Conocarpus erectus L. | button mangrove | Combretaceae
|
| CORA9 | Conocarpus racemosa L. | Laguncularia racemosa | Combretaceae
|
| CONOC | Conocarpus L. | mangrove | Combretaceae
|
| COCO38 | Conocephalum conicum (L.) Dumort. | | Conocephalaceae
|
| CONOC3 | Conocephalum Hill nom. cons. | | Conocephalaceae
|
| COBE4 | Conoclinium betonicifolium (P. Mill.) King & H.E. Robins. | betonyleaf thoroughwort | Asteraceae
|
| COCO13 | Conoclinium coelestinum (L.) DC. | blue mistflower | Asteraceae
|
| COGR10 | Conoclinium greggii (Gray) Small | palmleaf thoroughwort | Asteraceae
|
| CONOC4 | Conoclinium DC. | thoroughwort | Asteraceae
|
| COALM | Conopholis alpina Liebm. var. mexicana (Gray ex S. Wats.) Haynes | Mexican cancer-root | Orobanchaceae
|
| COAL6 | Conopholis alpina Liebm. | alpine cancer-root | Orobanchaceae
|
| COAM | Conopholis americana (L.) Wallr. f. | American cancer-root | Orobanchaceae
|
| COLU3 | Conopholis ludoviciana (Nutt.) Wood | Orobanche ludoviciana ssp. ludoviciana | Orobanchaceae
|
| COME7 | Conopholis mexicana Gray ex S. Wats. | Conopholis alpina var. mexicana | Orobanchaceae
|
| CONOP | Conopholis Wallr. | cancer-root | Orobanchaceae
|