| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| COSER | Convolvulus sepium L. var. repens (L.) Gray | Calystegia sepium ssp. angulata | Convolvulaceae
|
| COSE14 | Convolvulus sepium L. | Calystegia sepium ssp. sepium | Convolvulaceae
|
| COSE13 | Convolvulus sericatus House | Calystegia catesbiana | Convolvulaceae
|
| COSI4 | Convolvulus simulans Perry | Convolvulus equitans | Convolvulaceae
|
| COSO4 | Convolvulus soldanella L. | Calystegia soldanella | Convolvulaceae
|
| COSP7 | Convolvulus speciosus L. f. | Argyreia nervosa | Convolvulaceae
|
| COSPC2 | Convolvulus spithamaea L. var. catesbiana (Pursh) Tryon | Calystegia catesbiana | Convolvulaceae
|
| COSPP | Convolvulus spithamaeus L. var. pubescens (Gray) Fern. | Calystegia spithamaea ssp. purshiana | Convolvulaceae
|
| COSP6 | Convolvulus spithamaeus L. | Calystegia spithamaea ssp. spithamaea | Convolvulaceae
|
| COSU9 | Convolvulus subacaulis (Hook. & Arn.) Greene | Calystegia subacaulis ssp. subacaulis | Convolvulaceae
|
| COTI5 | Convolvulus tiliaceus auct. non Willd. | Ipomoea batatas | Convolvulaceae
|
| COTI6 | Convolvulus tiliifolius Desr. | Stictocardia tiliifolia | Convolvulaceae
|
| COTO4 | Convolvulus tomentellus Greene | Calystegia occidentalis ssp. occidentalis var. tomentella | Convolvulaceae
|
| COTR9 | Convolvulus trifidus Kunth | Ipomoea cordatotriloba var. torreyana | Convolvulaceae
|
| COUM2 | Convolvulus umbellatus L. | Merremia umbellata | Convolvulaceae
|
| COWA2 | Convolvulus wallichianus Spreng. | Wallich's bindweed | Convolvulaceae
|
| CONVO | Convolvulus L. | bindweed | Convolvulaceae
|
| COAP | Conyza apurensis Kunth | manzanilla horseweed | Asteraceae
|
| COAS4 | Conyza asteroides L. | Sericocarpus asteroides | Asteraceae
|
| COBI7 | Conyza bifoliata Walt. | Sericocarpus tortifolius | Asteraceae
|
| COBI3 | Conyza bilboana Remy | Conyza floribunda | Asteraceae
|
| COBOL | Conyza bonariensis (L.) Cronq. var. leiotheca (Blake) Cuatrec. | Conyza floribunda | Asteraceae
|
| COBO | Conyza bonariensis (L.) Cronq. | asthmaweed | Asteraceae
|
| COCAC3 | Conyza canadensis (L.) Cronq. var. canadensis | Canadian horseweed | Asteraceae
|
| COCAG | Conyza canadensis (L.) Cronq. var. glabrata (Gray) Cronq. | Canadian horseweed | Asteraceae
|
| COCAP3 | Conyza canadensis (L.) Cronq. var. pusilla (Nutt.) Cronq. | Canadian horseweed | Asteraceae
|
| COCA5 | Conyza canadensis (L.) Cronq. | Canadian horseweed | Asteraceae
|
| COCA22 | Conyza carolinensis Jacq. | Pluchea carolinensis | Asteraceae
|
| COCH3 | Conyza chilensis Spreng. | Conyza primulifolia | Asteraceae
|
| COCI3 | Conyza cinerea L. | Cyanthillium cinereum | Asteraceae
|
| COCO24 | Conyza cortesii Kunth | Pluchea carolinensis | Asteraceae
|
| COCOT | Conyza coulteri Gray var. tenuisecta Gray | Laennecia sophiifolia | Asteraceae
|
| COCOV2 | Conyza coulteri Gray var. virgata (Benth.) Gray | Laennecia coulteri | Asteraceae
|
| COCO4 | Conyza coulteri Gray | Laennecia coulteri | Asteraceae
|
| COER7 | Conyza eriophylla (Gray) Cronq. | Laennecia eriophylla | Asteraceae
|
| COFI3 | Conyza filaginoides (DC.) Hieron. | Laennecia filaginoides | Asteraceae
|
| COFL | Conyza floribunda Kunth | asthmaweed | Asteraceae
|
| COLI10 | Conyza linifolia L. | Sericocarpus linifolius | Asteraceae
|
| COLO8 | Conyza lobata L. | Neurolaena lobata | Asteraceae
|
| COLY | Conyza lyrata Kunth | Blumea viscosa | Asteraceae
|
| COOD2 | Conyza odorata L. | Pluchea odorata var. odorata | Asteraceae
|
| COPA17 | Conyza parva Cronq. | Conyza canadensis var. pusilla | Asteraceae
|
| COPR5 | Conyza primulifolia (Lam.) Cuatrec. & Lourteig | primroseleaf horseweed | Asteraceae
|
| CORA4 | Conyza ramosissima Cronq. | dwarf horseweed | Asteraceae
|
| COSC3 | Conyza schiedeana (Less.) Cronq. | Laennecia schiedeana | Asteraceae
|
| COSO2 | Conyza sophiifolia Kunth | Laennecia sophiifolia | Asteraceae
|
| COSU8 | Conyza subspathulata Cronq. | Conyza apurensis | Asteraceae
|
| COVI13 | Conyza viscosa P. Mill. | Blumea viscosa | Asteraceae
|
| CONYZ | Conyza Less. | horseweed | Asteraceae
|
| CODR2 | Cooperia drummondii Herbert | evening rainlily | Liliaceae
|
| COJO | Cooperia jonesii Cory | Jones' rainlily | Liliaceae
|
| COPE | Cooperia pedunculata Herbert | prairie lily | Liliaceae
|
| COSM | Cooperia smallii Alexander | Small's rainlily | Liliaceae
|
| COTR5 | Cooperia traubii Hayward | Traub's rainlily | Liliaceae
|
| COOPE | Cooperia Herbert | rainlily | Liliaceae
|
| COLA14 | Copaifera langsdorfii Desf. | Langsdorf's copaifera | Fabaceae
|
| COMU7 | Copaifera multijuga Hayne | copaifera | Fabaceae
|
| COOF2 | Copaifera officinalis (Jacq.) L. | copaiba | Fabaceae
|
| COPAI | Copaifera L. | copaifera | Fabaceae
|
| COAL13 | Copernicia alba Morong ex Morong & Britton | copernicia | Arecaceae
|
| COAU10 | Copernicia australis Becc. | Copernicia alba | Arecaceae
|
| COCE2 | Copernicia cerifera (Arruda) C. Martius | Copernicia prunifera | Arecaceae
|
| COPR6 | Copernicia prunifera (Miller) H. Moore | carnauba wax palm | Arecaceae
|
| COPER | Copernicia C. Martius ex Endl. | copernicia | Arecaceae
|
| COCY3 | Coprosma cymosa Hbd. | Hawai'i mirrorplant | Rubiaceae
|
| COEL3 | Coprosma elliptica Oliver | bog mirrorplant | Rubiaceae
|
| COERM | Coprosma ernodeoides Gray var. mauiensis St. John | Coprosma ernodeoides | Rubiaceae
|
| COER3 | Coprosma ernodeoides Gray | 'aiakanene | Rubiaceae
|
| COFAL | Coprosma fauriei Levl. var. lanaiensis Oliver | Coprosma foliosa | Rubiaceae
|
| COFAO | Coprosma fauriei Levl. var. oahuensis Oliver | Coprosma foliosa | Rubiaceae
|
| COFA3 | Coprosma fauriei Levl. | Coprosma foliosa | Rubiaceae
|
| COFO2 | Coprosma foliosa Gray | forest mirrorplant | Rubiaceae
|
| COKA | Coprosma kauensis (Gray) Heller | koi | Rubiaceae
|
| COLOO | Coprosma longifolia Gray var. oppositifolia Fosberg | Coprosma longifolia | Rubiaceae
|
| COLO4 | Coprosma longifolia Gray | Oahu mirrorplant | Rubiaceae
|
| COME6 | Coprosma menziesii Gray | hupilo | Rubiaceae
|
| COMO2 | Coprosma �molokaiensis St. John (pro sp.) | | Rubiaceae
|
| COMOC2 | Coprosma montana Hbd. var. crassa Oliver | Coprosma montana | Rubiaceae
|
| COMOO | Coprosma montana Hbd. var. orbicularis Oliver | Coprosma montana | Rubiaceae
|
| COMO3 | Coprosma montana Hbd. | alpine mirrorplant | Rubiaceae
|
| COOCK | Coprosma ochracea Oliver var. kaalae St. John | Coprosma ochracea | Rubiaceae
|
| COOCR | Coprosma ochracea Oliver var. rockiana Oliver | Coprosma ochracea | Rubiaceae
|
| COOC3 | Coprosma ochracea Oliver | Maui mirrorplant | Rubiaceae
|
| COPUS | Coprosma pubens Gray var. sessiliflora Oliver | Coprosma ochracea | Rubiaceae
|
| COPU8 | Coprosma pubens Gray | pubescent mirrorplant | Rubiaceae
|
| CORE4 | Coprosma repens A. Rich. | creeping mirrorplant | Rubiaceae
|
| CORH | Coprosma rhynchocarpa Gray | woodland mirrorplant | Rubiaceae
|
| COSE9 | Coprosma serrata St. John | Coprosma pubens | Rubiaceae
|
| COSK | Coprosma skottsbergiana Oliver | Coprosma foliosa | Rubiaceae
|
| COST9 | Coprosma stephanocarpa Hbd. | Coprosma foliosa | Rubiaceae
|
| COTE8 | Coprosma ternata Oliver | Molokai mirrorplant | Rubiaceae
|
| COWA4 | Coprosma waimeae Wawra | 'olena | Rubiaceae
|
| COPRO | Coprosma J.R. & G. Forst. | mirrorplant | Rubiaceae
|
| COLA9 | Coptidium lapponicum (L.) Gandog. | Ranunculus lapponicus | Ranunculaceae
|
| COAS | Coptis aspleniifolia Salisb. | fernleaf goldthread | Ranunculaceae
|
| COGR13 | Coptis groenlandica (Oeder) Fern. | Coptis trifolia | Ranunculaceae
|
| COLA3 | Coptis laciniata Gray | Oregon goldthread | Ranunculaceae
|
| COOC | Coptis occidentalis (Nutt.) Torr. & Gray | Idaho goldthread | Ranunculaceae
|
| COTRG | Coptis trifolia (L.) Salisb. ssp. groenlandica (Oeder) Hult�n | Coptis trifolia | Ranunculaceae
|
| COTRG2 | Coptis trifolia (L.) Salisb. var. groenlandica (Oeder) Fassett | Coptis trifolia | Ranunculaceae
|
| COTR2 | Coptis trifolia (L.) Salisb. | threeleaf goldthread | Ranunculaceae
|