| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| CYCAS | Cycas L. | cycad | Cycadaceae
|
| CYXA | Cyclachaena xanthifolia (Nutt.) Fresen. | Iva xanthifolia | Asteraceae
|
| CYHUH | Cycladenia humilis Benth. var. humilis | Sacramento waxydogbane | Apocynaceae
|
| CYHUJ | Cycladenia humilis Benth. var. jonesii (Eastw.) Welsh & Atwood | Jones' waxydogbane | Apocynaceae
|
| CYHUT | Cycladenia humilis Benth. var. tomentosa (Gray) Gray | Cycladenia humilis var. humilis | Apocynaceae
|
| CYHUV | Cycladenia humilis Benth. var. venusta (Eastw.) Woods. ex Munz | Sacramento waxydogbane | Apocynaceae
|
| CYHU | Cycladenia humilis Benth. | Sacramento waxydogbane | Apocynaceae
|
| CYJO2 | Cycladenia jonesii Eastw. | Cycladenia humilis var. jonesii | Apocynaceae
|
| CYCLA | Cycladenia Benth. | waxydogbane | Apocynaceae
|
| CYEU | Cyclamen europaeum of authors | Cyclamen purpurascens | Primulaceae
|
| CYHE5 | Cyclamen hederifolium L. | | Primulaceae
|
| CYNE4 | Cyclamen neapolitanum Ten. | Cyclamen hederifolium | Primulaceae
|
| CYPE10 | Cyclamen persicum Miller | florist's cyclamen | Primulaceae
|
| CYPU9 | Cyclamen purpurascens Miller | cyclamen | Primulaceae
|
| CYCLA3 | Cyclamen L. | cyclamen | Primulaceae
|
| CYDI | Cyclanthera dissecta (Torr. & Gray) Arn. | cutleaf cyclanthera | Cucurbitaceae
|
| CYPEE | Cyclanthera pedata (L.) Schrader var. edulis (Naudin) Cogn. | Cyclanthera pedata var. pedata | Cucurbitaceae
|
| CYPEP2 | Cyclanthera pedata (L.) Schrader var. pedata | cyclanthera | Cucurbitaceae
|
| CYPE11 | Cyclanthera pedata (L.) Schrader | cyclanthera | Cucurbitaceae
|
| CYCLA2 | Cyclanthera Schrad. | cyclanthera | Cucurbitaceae
|
| CYCA24 | Cyclobothra caerulea Kellogg | Calochortus caeruleus | Liliaceae
|
| CYCO16 | Cyclobothra coerulea Kellogg [orthographic variant] | Calochortus caeruleus | Liliaceae
|
| CYMO8 | Cyclobothra monophylla Lindl. | Calochortus monophyllus | Liliaceae
|
| CYVA4 | Cyclodictyon varians (Sull.) Kuntze | cyclodictyon moss | Callicostaceae
|
| CYCLO3 | Cyclodictyon Mitt. | cyclodictyon moss | Callicostaceae
|
| CYAL8 | Cyclodon alabamense (Vail) Small | Matelea alabamensis | Asclepiadaceae
|
| CYAT | Cycloloma atriplicifolium (Spreng.) Coult. | winged pigweed | Chenopodiaceae
|
| CYCLO | Cycloloma Moq. | cycloloma | Chenopodiaceae
|
| CYSE4 | Cyclopeltis semicordata (Sw.) J. Sm. | lime fern | Dryopteridaceae
|
| CYCLO2 | Cyclopeltis J. Sm. | cyclopeltis | Dryopteridaceae
|
| CYCR10 | Cyclopogon cranichoides (Griseb.) Schlechter | cranichis-like ladies'-tresses | Orchidaceae
|
| CYEL6 | Cyclopogon elatus (Sw.) Schlechter | tall ladies'-tresses | Orchidaceae
|
| CYMI7 | Cyclopogon miradorense Schlechter | | Orchidaceae
|
| CYCLO5 | Cyclopogon K. Presl | ladies'-tresses | Orchidaceae
|
| CYCY6 | Cyclosorus cyatheoides (Kaulfuss) Farw. | Thelypteris cyatheoides | Thelypteridaceae
|
| CYDE11 | Cyclosorus dentatus (Forsk.) Ching | Thelypteris dentata | Thelypteridaceae
|
| CYGO2 | Cyclosorus gongylodes (Schkuhr) Link | Thelypteris interrupta | Thelypteridaceae
|
| CYQU2 | Cyclosorus quadrangularis (F�e) Tardieu-Blot p.p. | Thelypteris hispidula var. versicolor | Thelypteridaceae
|
| CYSA5 | Cyclosorus sandwicensis (Brack.) Copeland | Pneumatopteris sandwicensis | Thelypteridaceae
|
| CYAM5 | Cyclospermum ammi Lag., non Sison ammi L. | Cyclospermum leptophyllum | Apiaceae
|
| CYLE7 | Cyclospermum leptophyllum (Pers.) Sprague ex Britt. & Wilson | marsh parsley | Apiaceae
|
| CYNO4 | Cyclospermum nodiflorum (L.) W.D.J. Koch | Apium nodiflorum | Apiaceae
|
| CYCLO4 | Cyclospermum Lag. | marsh parsley | Apiaceae
|
| CYTUM | Cycnium tubulosum (L. f.) Engl. ssp. montanum (N.E. Br.) O.J. Hansen | | Scrophulariaceae
|
| CYTU2 | Cycnium tubulosum (L. f.) Engl. | | Scrophulariaceae
|
| CYCNI | Cycnium E. Mey.ex Benth. | cycnium | Scrophulariaceae
|
| CYAE | Cydista aequinoctialis (L.) Miers | guard withe | Bignoniaceae
|
| CYDIS | Cydista Miers | withe | Bignoniaceae
|
| CYJA2 | Cydonia japonica (Thunb.) Pers. | Chaenomeles japonica | Rosaceae
|
| CYOB2 | Cydonia oblonga P. Mill. | quince | Rosaceae
|
| CYVU | Cydonia vulgaris Pers. | Cydonia oblonga | Rosaceae
|
| CYDON | Cydonia P. Mill. | cydonia | Rosaceae
|
| CYARA | Cylactis arctica (L.) Raf. ex B.D. Jackson ssp. acaulis (Michx.) W.A. Weber | Rubus arcticus ssp. acaulis | Rosaceae
|
| CYPU12 | Cylactis pubescens (Raf.) W.A. Weber | Rubus pubescens var. pubescens | Rosaceae
|
| CYAN12 | Cylindrocolea andersoni R. M. Schust. | | Cephaloziellaceae
|
| CYOB7 | Cylindrocolea obliqua (Douin) R. M. Schust. | | Cephaloziellaceae
|
| CYRH | Cylindrocolea rhizantha (Mont.) R. M. Schust. | | Cephaloziellaceae
|
| CYLIN | Cylindrocolea R. M. Schust. | | Cephaloziellaceae
|
| CYIM2 | Cylindropuntia imbricata (Haw.) F.M. Knuth | Opuntia imbricata var. imbricata | Cactaceae
|
| CYMU8 | Cylindropuntia �munzii (C.B. Wolf) Backeberg | Opuntia munzii | Cactaceae
|
| CYWH | Cylindropuntia whipplei (Engelm. & Bigelow) F.M. Knuth | Opuntia whipplei | Cactaceae
|
| CYCY5 | Cylindropyrum cylindricum (Host) A. L�ve | Aegilops cylindrica | Poaceae
|
| CYMU | Cymbalaria muralis P.G. Gaertn., B. Mey. & Scherb. | Kenilworth ivy | Scrophulariaceae
|
| CYMBA | Cymbalaria Hill | cymbalaria | Scrophulariaceae
|
| CYOC3 | Cymbia occidentalis (Nutt.) Standl. | Krigia occidentalis | Asteraceae
|
| CYMBI | Cymbidium Sw. | cymbidium | Orchidaceae
|
| CYRE12 | Cymbocarpa refracta Miers | cat's milk | Burmanniaceae
|
| CYMBO2 | Cymbocarpa Miers | cymbocarpa | Burmanniaceae
|
| CYCI | Cymbopogon citratus (DC. ex Nees) Stapf | lemon grass | Poaceae
|
| CYFL2 | Cymbopogon flexuosus (Nees ex Steudel) J. F. Watson | east indian lemongrass | Poaceae
|
| CYJW | Cymbopogon jwarancusa (Jones) Schultes | Iwarancusa grass | Poaceae
|
| CYMA15 | Cymbopogon martinii (Roxb.) J. F. Watson | rosha grass | Poaceae
|
| CYNA | Cymbopogon nardus (L.) Rendle | citronella grass | Poaceae
|
| CYRE | Cymbopogon refractus (R. Br.) A. Camus | barbwire grass | Poaceae
|
| CYSC8 | Cymbopogon schoenanthus (L.) Sprengel | camel grass | Poaceae
|
| CYWI6 | Cymbopogon winterianus Jowitt | cymbopogon grass | Poaceae
|
| CYMBO | Cymbopogon Spreng. | lemon grass | Poaceae
|
| CYUR2 | Cymburus urticifolius sensu Salisb. (excl. type) | Stachytarpheta urticifolia | Verbenaceae
|
| CYFI3 | Cymodocea filiformis (Kuetz.) Correll | manateegrass | Cymodoceaceae
|
| CYMA18 | Cymodocea manatorum Aschers. | Cymodocea filiformis | Cymodoceaceae
|
| CYRO9 | Cymodocea rotundata Ehrenb. & Hempr. ex Aschers. | cymodocea | Cymodoceaceae
|
| CYSE10 | Cymodocea serrulata (R. Br.) Aschers. & Magnus | cymodocea | Cymodoceaceae
|
| CYMOD | Cymodocea Koenig | cymodocea | Cymodoceaceae
|
| CYAC7 | Cymophora accedens (S.F. Blake) B.L. Turner & Powell | | Asteraceae
|
| CYMOP3 | Cymophora B.L. Robins. | cymophora | Asteraceae
|
| CYFR | Cymophyllus fraseri (Andr.) Mackenzie ex Britt. | Cymophyllus fraserianus | Cyperaceae
|
| CYFR4 | Cymophyllus fraserianus (Ker-Gawl.) Kartesz & Gandhi | Fraser's cymophyllus | Cyperaceae
|
| CYMOP | Cymophyllus Mackenzie ex Britt. | cymophyllus | Cyperaceae
|
| CYAB | Cymopterus aboriginum M.E. Jones | Indian springparsley | Apiaceae
|
| CYACA | Cymopterus acaulis (Pursh) Raf. var. acaulis | plains springparsley | Apiaceae
|
| CYACF | Cymopterus acaulis (Pursh) Raf. var. fendleri (Gray) Goodrich | Fendler's springparsley | Apiaceae
|
| CYACG | Cymopterus acaulis (Pursh) Raf. var. greeleyorum J. Grimes & Packard | Greeley springparsley | Apiaceae
|
| CYACH | Cymopterus acaulis (Pursh) Raf. var. higginsii (Welsh) Goodrich | Higgins' springparsley | Apiaceae
|
| CYACP | Cymopterus acaulis (Pursh) Raf. var. parvus Goodrich | plains springparsley | Apiaceae
|
| CYAC | Cymopterus acaulis (Pursh) Raf. | plains springparsley | Apiaceae
|
| CYAL9 | Cymopterus alpinus Gray | Oreoxis alpina ssp. alpina | Apiaceae
|
| CYAN8 | Cymopterus anisatus Gray | Aletes anisatus | Apiaceae
|
| CYBA8 | Cymopterus bakeri (Coult. & Rose) M.E. Jones | Oreoxis bakeri | Apiaceae
|
| CYBA3 | Cymopterus basalticus M.E. Jones | basalt springparsley | Apiaceae
|
| CYBE2 | Cymopterus beckii Welsh & Goodrich | featherleaf springparsley | Apiaceae
|
| CYBI | Cymopterus bipinnatus S. Wats. | Cymopterus nivalis | Apiaceae
|