| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| COCA44 | Cololejeunea cardiocarpa (Mont.) R. M. Schust. | | Lejeuneaceae
|
| COCO37 | Cololejeunea contractiloba A. Evans | | Lejeuneaceae
|
| COMA24 | Cololejeunea macounii (Spruce ex Underw.) A. Evans | | Lejeuneaceae
|
| COMIM4 | Cololejeunea minutissima (Sm.) Schiffn. ssp. minutissima | | Lejeuneaceae
|
| COMIM5 | Cololejeunea minutissima (Sm.) Schiffn. ssp. myriocarpa (Nees & Mont.) R. M. Schust. | | Lejeuneaceae
|
| COMI15 | Cololejeunea minutissima (Sm.) Schiffn. | | Lejeuneaceae
|
| COOR12 | Cololejeunea ornata A. Evans | | Lejeuneaceae
|
| COSE18 | Cololejeunea setiloba A. Evans | | Lejeuneaceae
|
| COSU17 | Cololejeunea subcristata A. Evans | | Lejeuneaceae
|
| COLOL | Cololejeunea (Spruce) Schiffn. | | Lejeuneaceae
|
| COME8 | Coloradoa mesae-verdae Boissevain ex Boissevain & C. Davids. | Sclerocactus mesae-verdae | Cactaceae
|
| COFU | Colpodium fulvum (Trin.) Griseb. | Arctophila fulva | Poaceae
|
| COLA11 | Colpodium latifolium R. Br. | Arctagrostis latifolia ssp. latifolia | Poaceae
|
| COVA | Colpodium vahlianum (Liebm.) Nevski | Puccinellia vahliana | Poaceae
|
| COWR | Colpodium wrightii Scribn. & Merr. | Puccinellia wrightii | Poaceae
|
| COAR3 | Colubrina arborescens (P. Mill.) Sarg. | greenheart | Rhamnaceae
|
| COAS3 | Colubrina asiatica (L.) Brongn. | Asian nakedwood | Rhamnaceae
|
| COCA18 | Colubrina californica I.M. Johnston | Las Animas nakedwood | Rhamnaceae
|
| COCO19 | Colubrina colubrina (Jacq.) Millsp. | Colubrina arborescens | Rhamnaceae
|
| COCUF | Colubrina cubensis (Jacq.) Brongn. var. floridana M.C. Johnston | Cuban nakedwood | Rhamnaceae
|
| COCU | Colubrina cubensis (Jacq.) Brongn. | Cuban nakedwood | Rhamnaceae
|
| COEL2 | Colubrina elliptica (Sw.) Briz. & Stern | soldierwood | Rhamnaceae
|
| COGLA | Colubrina glandulosa Perkins var. antillana (M.C. Johnston) M.C. Johnston | glandular nakedwood | Rhamnaceae
|
| COGL5 | Colubrina glandulosa Perkins | glandular nakedwood | Rhamnaceae
|
| COGR7 | Colubrina greggii S. Wats. | Sierra nakedwood | Rhamnaceae
|
| COOP | Colubrina oppositifolia Brongn. ex Mann | kauila | Rhamnaceae
|
| CORE7 | Colubrina reclinata (L'H�r.) Brongn. | Colubrina elliptica | Rhamnaceae
|
| CORUA | Colubrina rufa (Vell.) Reissek var. antillana M.C. Johnston | Colubrina glandulosa var. antillana | Rhamnaceae
|
| COST6 | Colubrina stricta Engelm. ex M.C. Johnston | comal nakedwood | Rhamnaceae
|
| COTEC2 | Colubrina texensis (Torr. & Gray) Gray var. californica (I.M. Johnston) L. Benson | Colubrina californica | Rhamnaceae
|
| COTEP | Colubrina texensis (Torr. & Gray) Gray var. pedunculata M.C. Johnston | Texan hogplum | Rhamnaceae
|
| COTET | Colubrina texensis (Torr. & Gray) Gray var. texensis | Texan hogplum | Rhamnaceae
|
| COTE6 | Colubrina texensis (Torr. & Gray) Gray | Texan hogplum | Rhamnaceae
|
| COUR | Colubrina urbanii M.C. Johnston | Colubrina verrucosa | Rhamnaceae
|
| COVE6 | Colubrina verrucosa (Urban) M.C. Johnston | Urban's nakedwood | Rhamnaceae
|
| COLUB | Colubrina L.C. Rich. ex Brongn. | nakedwood | Rhamnaceae
|
| COBU6 | Columbia burreti Kanehira | | Tiliaceae
|
| COLUM3 | Columbia Pers. | | Tiliaceae
|
| COHA5 | Columbiadoria hallii (Gray) Nesom | Hall's columbiadoria | Asteraceae
|
| COLUM2 | Columbiadoria Nesom | columbiadoria | Asteraceae
|
| COAM6 | Columnea ambigua (Urban) Morley | tibey de cresta | Gesneriaceae
|
| COSCT | Columnea scandens L. var. tulae (Urban) Wiehler | tibey parasito | Gesneriaceae
|
| COSC11 | Columnea scandens L. | tibey parasito | Gesneriaceae
|
| COTU3 | Columnea tulae Urban | Columnea scandens var. tulae | Gesneriaceae
|
| COLUM | Columnea L. | columnea | Gesneriaceae
|
| COAR6 | Colutea arborescens L. | bladder senna | Fabaceae
|
| COLUT | Colutea L. | colutea | Fabaceae
|
| COCA32 | Comandra californica Eastw. ex Rydb. | Comandra umbellata ssp. californica | Santalaceae
|
| COLI12 | Comandra lividum Richards. | Geocaulon lividum | Santalaceae
|
| COPA26 | Comandra pallida A. DC. | Comandra umbellata ssp. pallida | Santalaceae
|
| CORI3 | Comandra richardsiana Fern. | Comandra umbellata ssp. umbellata | Santalaceae
|
| COUMC | Comandra umbellata (L.) Nutt. ssp. californica (Eastw. ex Rydb.) Piehl | California bastard toadflax | Santalaceae
|
| COUMP | Comandra umbellata (L.) Nutt. ssp. pallida (A. DC.) Piehl | pale bastard toadflax | Santalaceae
|
| COUMU | Comandra umbellata (L.) Nutt. ssp. umbellata | bastard toadflax | Santalaceae
|
| COUMA | Comandra umbellata (L.) Nutt. var. angustifolia (A. DC.) Torr. | Comandra umbellata ssp. pallida | Santalaceae
|
| COUMC2 | Comandra umbellata (L.) Nutt. var. californica (Eastw. ex Rydb.) C.L. Hitchc. | Comandra umbellata ssp. californica | Santalaceae
|
| COUMP2 | Comandra umbellata (L.) Nutt. var. pallida (A. DC.) M.E. Jones | Comandra umbellata ssp. pallida | Santalaceae
|
| COUM | Comandra umbellata (L.) Nutt. | bastard toadflax | Santalaceae
|
| COMAN | Comandra Nutt. | bastard toadflax | Santalaceae
|
| CODID2 | Comarostaphylis diversifolia (Parry) Greene ssp. diversifolia | summer holly | Ericaceae
|
| CODIP | Comarostaphylis diversifolia (Parry) Greene ssp. planifolia (Jepson) G. Wallace ex Thorne | summer holly | Ericaceae
|
| CODIP2 | Comarostaphylis diversifolia (Parry) Greene var. planifolia Jepson | Comarostaphylis diversifolia ssp. planifolia | Ericaceae
|
| CODI3 | Comarostaphylis diversifolia (Parry) Greene | summer holly | Ericaceae
|
| COMAR | Comarostaphylis Zucc. | summer holly | Ericaceae
|
| COPA28 | Comarum palustre L. | purple marshlocks | Rosaceae
|
| COMAR3 | Comarum L. | comarum | Rosaceae
|
| COTE13 | Comastoma tenellum (Rottb.) Toyokuni | Gentianella tenella ssp. tenella | Gentianaceae
|
| COCA36 | Combea californica (Th. Fr.) Follmann & M. Geyer | Schizopelte californica | Roccellaceae
|
| COTE15 | Combretum tetralophum C.B. Clarke | | Combretaceae
|
| COMBR | Combretum Loefl. | | Combretaceae
|
| COAN8 | Commelina angustifolia Michx. | Commelina erecta var. angustifolia | Commelinaceae
|
| COAN7 | Commelina anomala (Torr.) Woods. | Tinantia anomala | Commelinaceae
|
| COBE2 | Commelina benghalensis L. | jio | Commelinaceae
|
| COCA17 | Commelina caroliniana Walt. | Carolina dayflower | Commelinaceae
|
| COCO28 | Commelina coelestis Willd. | commelina | Commelinaceae
|
| COCOC3 | Commelina communis L. var. communis | Asiatic dayflower | Commelinaceae
|
| COCOL | Commelina communis L. var. ludens (Miq.) C.B. Clarke | Asiatic dayflower | Commelinaceae
|
| COCO3 | Commelina communis L. | Asiatic dayflower | Commelinaceae
|
| COCR4 | Commelina crispa Woot. | Commelina erecta var. angustifolia | Commelinaceae
|
| CODE9 | Commelina debilis Ledeb. | Commelina communis var. ludens | Commelinaceae
|
| CODE10 | Commelina deficiens Hook. | Commelina virginica | Commelinaceae
|
| CODID | Commelina dianthifolia Delile var. dianthifolia | birdbill dayflower | Commelinaceae
|
| CODIL | Commelina dianthifolia Delile var. longispatha (Torr.) Brashier | birdbill dayflower | Commelinaceae
|
| CODI4 | Commelina dianthifolia Delile | birdbill dayflower | Commelinaceae
|
| CODID3 | Commelina diffusa Burm. f. var. diffusa | climbing dayflower | Commelinaceae
|
| CODIG | Commelina diffusa Burm. f. var. gigas (Small) Faden | climbing dayflower | Commelinaceae
|
| CODI5 | Commelina diffusa Burm. f. | climbing dayflower | Commelinaceae
|
| COEL4 | Commelina elegans Kunth | Commelina erecta var. erecta | Commelinaceae
|
| COERA | Commelina erecta L. var. angustifolia (Michx.) Fern. | whitemouth dayflower | Commelinaceae
|
| COERC | Commelina erecta L. var. crispa (Woot.) Palmer & Steyermark | Commelina erecta var. angustifolia | Commelinaceae
|
| COERD | Commelina erecta L. var. deamiana Fern. | whitemouth dayflower | Commelinaceae
|
| COERE | Commelina erecta L. var. erecta | whitemouth dayflower | Commelinaceae
|
| COERG | Commelina erecta L. var. greenei Fassett | Commelina erecta var. deamiana | Commelinaceae
|
| COER | Commelina erecta L. | whitemouth dayflower | Commelinaceae
|
| COFO3 | Commelina forskaolii Vahl | rat's ear | Commelinaceae
|
| COGI2 | Commelina gigas Small | Commelina diffusa var. gigas | Commelinaceae
|
| COLA19 | Commelina latifolia Hochst. ex A. Rich. | | Commelinaceae
|
| COLIL | Commelina linearis Benth. var. longispatha Torr. | Commelina dianthifolia var. longispatha | Commelinaceae
|
| COLO11 | Commelina longicaulis Jacq. | Commelina diffusa var. diffusa | Commelinaceae
|
| COLO6 | Commelina longifolia Michx. | Commelina virginica | Commelinaceae
|
| CONA | Commelina nashii Small | Commelina erecta var. angustifolia | Commelinaceae
|