| Accepted Latin Names | Common Name | In Kent? | Type | Kent ref. | Status | Authority | Record No. |
|---|---|---|---|---|---|---|---|
| Cabomba caroliniana | Carolina Water-shield | Yes S1 | A1 | 26A--CAB--car | Ne | A. Gray | 0920005463 |
| Cachrys uechtritzii | Clement | A3 | 107--CAC--uec | (Boiss. & Hausskn.) Herrnst. & Heyn | 0920006030 | ||
| Caesalpinia spinosa | Tara | Clement | A3 | 76A--CAE--spi | (Molina) Kuntze | 0920006031 | |
| Cakile maritima | Sea Rocket | Page 13 | A1 | 62--39--1 | N | Scop. | 0920000291 |
| Cakile maritima subsp. integrifolia | Yes | A1 | 62--39--1--a | (Hornem.) Hyl. ex Greuter & Burdet | 0920000291 | ||
| Calamagrostis canescens | Purple Small-reed | Yes | A1 | 153--40--2 | N | (F.H. Wigg.) Roth | 0920000292 |
| Calamagrostis canescens x stricta = C. x gracilescens | Yes | A1 | 153--40--2 x 4 | (Blytt) Blytt | 0920002913 | ||
| Calamagrostis epigejos | Wood Small-reed | Page 13 | A1 | 153--40--1 | N | (L.) Roth | 0920000293 |
| Calamagrostis epigejos x Ammophila arenaria = X Calammophila baltica | Purple Marram | Yes | A1 | 153--40 x 41--1 x 1 | (Flgg‚ ex Schrad.) Brand | 0920000096 | |
| Calamagrostis purpurea | Scandinavian Small-reed | Yes | A1 | 153--40--3 | N | (Trin.) Trin. | 0920002646 |
| Calamagrostis purpurea subsp. phragmitoides | Yes | A1 | 153--40--3--a | (Hartm.) Tzvelev | 0920002646 | ||
| Calamagrostis scotica | Scottish Small-reed | Yes | A1 | 153--40--5 | N | (Druce) Druce | 0920000295 |
| Calamagrostis stricta | Narrow Small-reed | Yes | A1 | 153--40--4 | N | (Timm) Koeler | 0920000294 |
| Calandrinia ciliata | Red-maids | Clement | A3 | 45--CAL--cil | (Ruiz & Pav.) DC. | 0920007976 | |
| Calandrinia umbellata | Rock Purslane | Clement | A3 | 45--CAL--umb | (Ru¡z & Pav.) DC. | 0920004202 | |
| Calceolaria biflora | Clement | A3 | 124--6--bif | Lam. | 0920006033 | ||
| Calceolaria chelidonioides | Slipperwort | Yes | A1 | 124--6--1 | Ne | Kunth | 0920007199 |
| Calceolaria integrifolia | Bush Slipperwort | Clement | A3 | 124--6--int | Murray | 0920007977 | |
| Calceolaria x herbeohybrida | Florists' Slipperwort | Clement | A3 | 124--6--her | Voss | 0920006034 | |
| Caldesia parnassiifolia | Parnassus-leaved Water-plantain | Clement | A3 | 137--CAL--par | (L.) Parl. | 0920006035 | |
| Calendula arvensis | Field Marigold | Yes | A1 | 135--73--2 | Ne | L. | 0920000299 |
| Calendula officinalis | Pot Marigold | Yes | A1 | 135--73--1 | Ne | L. | 0920000300 |
| Calepina irregularis | White Ball-mustard | Clement | A3 | 62--CAL--irr | (Asso) Thell. | 0920006036 | |
| Calla palustris | Bog Arum | Yes | A1 | 147--3--1 | Ne | L. | 0920000301 |
| Callistephus chinensis | China Aster | Stace | A2 | 135--CAE--chi | Ca | (L.) Nees | 0920007978 |
| Callitriche brutia | Pedunculate Water-starwort | Yes | A1 | 120--1--6 | N | Petagna | 0920000303.2 |
| Callitriche hamulata | Intermediate Water-starwort | Yes | A1 | 120--1--7 | N | Ktz. ex W.D.J. Koch | 0920000303.1 |
| Callitriche hamulata agg. | Aggregate | AK | 120--1--- | ||||
| Callitriche hermaphroditica | Autumnal Water-starwort | Yes | A1 | 120--1--1 | N | L. | 0920000302 |
| Callitriche obtusangula | Blunt-fruited Water-starwort | Yes | A1 | 120--1--5 | N | Le Gall | 0920000304 |
| Callitriche palustris | Narrow-fruited Water-starwort | Yes S2 | A1 | 120--1--pal | N | L. | |
| Callitriche platycarpa | Various-leaved Water-starwort | Yes | A1 | 120--1--4 | N | Ktz. | 0920000307.1 |
| Callitriche stagnalis | Common Water-starwort | Page 13 | A1 | 120--1--3 | N | Scop. | 0920000307.2 |
| Callitriche truncata | Short-leaved Water-starwort | Yes | A1 | 120--1--2 | N | Guss. | 0920000308 |
| Callitriche truncata subsp. occidentalis | Yes | A1 | 120--1--2--a | (Rouy) Braun-Blanq. | 0920000308 | ||
| Calluna vulgaris | Heather | Page 13 | A1 | 65--11--1 | N | (L.) Hull | 0920000309 |
| Calocedrus decurrens | Californian Incense-cedar | Clement | A3 | 21--CAL--dec | (Torrey) Florin | 0920003610 | |
| Calocephalus knappii | Clement | A3 | 135--CAH--kna | (F. Muell.) Ewart & J.W. White | 0920006037 | ||
| Calotis cuneifolia | Bur-daisy | Stace | A2 | 135--CAI--cun | Ca | R. Br. | 0920007979 |
| Calotis dentex | White Bur-daisy | Clement | A3 | 135--CAI--den | R. Br. | 0920006038 | |
| Calotis hispidula | Hairy Bur-daisy | Clement | A3 | 135--CAI--his | (F. Muell.) F. Muell. | 0920007980 | |
| Calotis lappulacea | Yellow Bur-daisy | Clement | A3 | 135--CAI--lap | Benth. | 0920007981 | |
| Caltha palustris | Marsh-marigold | Page 13 | A1 | 28--1--1 | N | L. | 0920000310 |
| Calycadenia multiglandulosa | Sticky Calycadenia | Clement | A3 | 135--CAL--mul | DC. | 0920006039 | |
| Calypso bulbosa | Calypso | Clement | A3 | 162--CAL--bul | (L.) Oakes | 0920006040 | |
| Calystegia pulchra | Hairy Bindweed | Yes | A1 | 111--3--3 | Ne | Brummitt & Heywood | 0920002266 |
| Calystegia pulchra x silvatica = C. x howittiorum | Yes | A1 | 111--3--3 x 4 | Brummitt | 0920004387 | ||
| Calystegia sepium | Hedge Bindweed | Page 13 | A1 | 111--3--2 | N | (L.) R. Br. | 0920000311 |
| Calystegia sepium agg. | Aggregate | AK | 111--3--- | ||||
| Calystegia sepium subsp. americana | Clement | A3 | 111--3--2--c | (Sims) Brummitt | 0920006041 | ||
| Calystegia sepium subsp. roseata | Yes | A1 | 111--3--2--b | N | Brummitt | 0920000311.1 | |
| Calystegia sepium subsp. sepium | Yes | A1 | 111--3--2--a | 0920000311.2 | |||
| Calystegia sepium subsp. spectabilis | Clement | A3 | 111--3--2--d | Brummitt | 0920000311.5 | ||
| Calystegia sepium x pulchra = C. x scanica | Yes | A1 | 111--3--2 x 3 | Brummitt | 0920007200 | ||
| Calystegia sepium x silvatica = C. x lucana | Yes | A1 | 111--3--2 x 4 | ? | (Ten.) G. Don | 0920004386 | |
| Calystegia silvatica | Large Bindweed | Page 13 | A1 | 111--3--4 | Ne | (Kit.) Griseb. | 0920000313 |
| Calystegia silvatica subsp. disjuncta | Yes S3 | A1 | 111--3--4--b | Ne | Brummitt | ||
| Calystegia silvatica subsp. fraterniflora | Clement | A3 | 111--3--4--b | (Mack. & Bush) Brummitt | 0920000313.5 | ||
| Calystegia silvatica subsp. silvatica | Yes S3 | A1 | 111--3--4--a | Ne | |||
| Calystegia soldanella | Sea Bindweed | Page 13 | A1 | 111--3--1 | N | (L.) R. Br. | 0920000312 |
| Camassia quamash | Common Camash | Clement | A3 | 158--CAM--qua | (Pursh) Greene | 0920006043 | |
| Camelina alyssum | Clement | A3 | 62--24--aly | (Mill.) Thell. | 0920004351 | ||
| Camelina hispida | Clement | A3 | 62--24--his | Boiss. | 0920006044 | ||
| Camelina macrocarpa | Clement | A3 | 62--24--mac | Andrz. ex DC. | 0920005421 | ||
| Camelina microcarpa | Lesser Gold-of-pleasure | Stace | A2 | 62--24--mic | Ca | Andrz. ex DC. | 0920002567 |
| Camelina rumelica | Clement | A3 | 62--24--rum | Velen. | 0920004353 | ||
| Camelina sativa | Gold-of-pleasure | Yes | A1 | 62--24--1 | Ar | (L.) Crantz | 0920004352 |
| Campanula alliariifolia | Cornish Bellflower | Yes | A1 | 129--1--6 | Ne | Willd. | 0920007201 |
| Campanula bononiensis | Pale Bellflower | Clement | A3 | 129--1--bon | L. | 0920006045 | |
| Campanula carpatica | Tussock Bellflower | Clement | A3 | 129--1--car | Jacq. | 0920007983 | |
| Campanula cochleariifolia | Fairy's-thimble | Yes S2 | A1 | 129--1--coc | Lam. | 0920006046 | |
| Campanula fragilis | Italian Bellflower | Yes S1 | A1 | 129--1--fra | Ne | Cirillo | 0920007984 |
| Campanula garganica | Adriatic Bellflower | Clement | A3 | 129--1--gar | Ten. | 0920006047 | |
| Campanula glomerata | Clustered Bellflower | Page 13 | A1 | 129--1--7 | N | L. | 0920000315 |
| Campanula glomerata subsp. elliptica | Clement | A3 | 129--1--7--b | (Kit. ex Schult.) O. Schwarz | 0920000315.1 | ||
| Campanula glomerata subsp. glomerata | Other | AT | 129--1--7--a | ||||
| Campanula lactiflora | Milky Bellflower | Yes | A1 | 129--1--3 | Ne | M. Bieb. | 0920004396 |
| Campanula latifolia | Giant Bellflower | Page 13 | A1 | 129--1--11 | N | L. | 0920000316 |
| Campanula medium | Canterbury-bells | Yes | A1 | 129--1--5 | Ne | L. | 0920000317 |
| Campanula patula | Spreading Bellflower | Yes | A1 | 129--1--1 | N | L. | 0920000318 |
| Campanula persicifolia | Peach-leaved Bellflower | Yes | A1 | 129--1--4 | Ne | L. | 0920000319 |
| Campanula portenschlagiana | Adria Bellflower | Yes | A1 | 129--1--9 | Ne | Schult. | 0920002640 |
| Campanula poscharskyana | Trailing Bellflower | Yes | A1 | 129--1--10 | Ne | Degen | 0920002641 |
| Campanula pyramidalis | Chimney Bellflower | Yes | A1 | 129--1--8 | Ne | L. | 0920007202 |
| Campanula rapunculoides | Creeping Bellflower | Yes | A1 | 129--1--13 | Ne | L. | 0920000320 |
| Campanula rapunculus | Rampion Bellflower | Yes | A1 | 129--1--2 | Ar | L. | 0920000321 |
| Campanula rhomboidalis | Broad-leaved Harebell | Yes | A1 | 129--1--14 | Ne | L. | 0920007203 |
| Campanula rotundifolia | Harebell | Page 13 | A1 | 129--1--15 | N | L. | 0920000322 |
| Campanula trachelium | Nettle-leaved Bellflower | Page 13 | A1 | 129--1--12 | N | L. | 0920000323 |
| Campsis radicans | Trumpet-creeper | Clement | A3 | 127B--CAM--rad | (L.) Seem. ex Bureau | 0920006049 | |
| Canna indica | Indian-shot | Clement | A3 | 156A--CAN--ind | L. | 0920006050 | |
| Cannabis sativa | Hemp | Yes | A1 | 34--1--1 | Ca | L. | 0920000324 |
| Capnophyllum peregrinum | Clement | A3 | 107--CAP--per | (L.) Lange | 0920006051 | ||
| Capsella bursa-pastoris | Shepherd's-purse | Page 13 | A1 | 62--25--1 | Ar | (L.) Medik. | 0920000325 |
| Capsella bursa-pastoris x rubella = C. x gracilis | Yes | A1 | 62--25--1 x 2 | Gren. | 0920007204 | ||
| Capsella rubella | Pink Shepherd's-purse | Yes | A1 | 62--25--2 | Ne | Reut. | 0920000326 |
| Capsicum annuum | Sweet Pepper | Stace | A2 | 110--CAP--ann | Ca | L. | 0920007985 |
| Caragana arborescens | Siberian Pea-tree | Clement | A3 | 77--CAR--arb | Lam. | 0920006052 | |
| Cardamine amara | Large Bitter-cress | Page 13 | A1 | 62--14--3 | N | L. | 0920000327 |
| Cardamine bulbifera | Coralroot | Yes | A1 | 62--14--1 | N | (L.) Crantz | 0920000625 |
| Cardamine chelidonia | Clement | A3 | 62--14--che | L. | 0920004042 | ||
| Cardamine corymbosa | New Zealand Bitter-cress | Yes S1 | A1 | 62--14--cor | Ne | Hook. f. | 0920003326 |
| Cardamine flexuosa | Wavy Bitter-cress | Page 13 | A1 | 62--14--7 | N | With. | 0920000328 |
| Cardamine flexuosa x hirsuta = C. x zahlbruckneriana | Yes | A1 | 62--14--7 x 8 | O.E. Schulz | 0920007205 | ||
| Cardamine glanduligera | Clement | A3 | 62--14--gla | O. Schwarz | 0920006053 | ||
| Cardamine heptaphylla | Pinnate Coralroot | Yes S2 | A1 | 62--14--hep | Ne | (Vill.) O.E. Schulz | 0920007986 |
| Cardamine hirsuta | Hairy Bitter-cress | Page 13 | A1 | 62--14--8 | N | L. | 0920000329 |
| Cardamine impatiens | Narrow-leaved Bitter-cress | Yes | A1 | 62--14--6 | N | L. | 0920000330 |
| Cardamine kitaibelii | Kitaibel's Bitter-cress | Clement | A3 | 62--14--kit | Bech. | 0920006054 | |
| Cardamine laciniata | Cut-leaved Bitter-cress | Clement | A3 | 62--14--lac | (Muhl.) A.W. Wood | 0920006055 | |
| Cardamine pentaphyllos | Five-leaflet Bitter-cress | Clement | A3 | 62--14--pen | (L.) Crantz | 0920006056 | |
| Cardamine pratensis | Cuckooflower | Page 13 | A1 | 62--14--5 | N | L. | 0920000331 |
| Cardamine pratensis x flexuosa = C. x fringsii | Yes | A1 | 62--14--5 x 7 | F. Wirtg. | 0920002681 | ||
| Cardamine raphanifolia | Greater Cuckooflower | Yes | A1 | 62--14--4 | Ne | Pourr. | 0920002557 |
| Cardamine trifolia | Trefoil Cress | Yes | A1 | 62--14--2 | Ne | L. | 0920002558 |
| Cardiospermum halicacabum | Clement | A3 | 97--CAR--hal | L. | 0920006057 | ||
| Carduncellus caeruleus | Clement | A3 | 135--CAN--cae | (L.) C. Presl | 0920006058 | ||
| Carduus argentatus | Clement | A3 | 135--5--arg | L. | 0920006059 | ||
| Carduus chrysacanthus | Clement | A3 | 135--5--chr | L. | 0920006060 | ||
| Carduus crispus | Welted Thistle | Page 13 | A1 | 135--5--3 | N | L. | 0920000335 |
| Carduus crispus subsp. multiflorus | Yes | A1 | 135--5--3--a | (Gaudin) Gremli | 0920000335 | ||
| Carduus crispus x nutans = C. x stangii | Yes S1 | A1 | 135--5--3 x 4 | N | H. Buek ex Nyman | 0920000336 | |
| Carduus hamulosus | Clement | A3 | 135--5--ham | Ehrh. | 0920006061 | ||
| Carduus leucophyllus | Clement | A3 | 135--5--leu | Turcz. | 0920006062 | ||
| Carduus macrocephalus | Giant Thistle | Clement | A3 | 135--5--mac | Desf. | 0920007987 | |
| Carduus nigrescens | Clement | A3 | 135--5--nig | Vill. | 0920006063 | ||
| Carduus nutans | Musk Thistle | Page 13 | A1 | 135--5--4 | N | L. | 0920000337 |
| Carduus pycnocephalus | Plymouth Thistle | Yes | A1 | 135--5--2 | Ne | L. | 0920000338 |
| Carduus tenuiflorus | Slender Thistle | Page 13 | A1 | 135--5--1 | N | Curtis | 0920000339 |
| Carduus thoermeri | Clement | A3 | 135--5--tho | Weinm. | 0920005653 | ||
| Carduus vivariensis | Clement | A3 | 135--5--viv | Jord. | 0920006064 | ||
| Carex acuta | Slender Tufted-sedge | Yes | A1 | 152--16--65 | N | L. | 0920000340 |
| Carex acuta x elata = C. x prolixa | Yes | A1 | 152--16--65 x 68 | Fr. | 0920002890 | ||
| Carex acuta x nigra | Yes | A1 | 152--16--65 x 67 | 0920002608 | |||
| Carex acutiformis | Lesser Pond-sedge | Page 15 | A1 | 152--16--25 | N | Ehrh. | 0920000341 |
| Carex acutiformis x acuta = C. x subgracilis | Yes | A1 | 152--16--25 x 65 | Druce | 0920004349 | ||
| Carex acutiformis x riparia = C. x sooi | Yes S1 | A1 | 152--16--25 x 26 | J kucs | 0920003327 | ||
| Carex acutiformis x vesicaria = C. x ducellieri | Yes | A1 | 152--16--25 x 29 | Beauverd | 0920007211 | ||
| Carex appressa | Tall Sedge | Clement | A3 | 152--16--app | R. Br. | 0920006065 | |
| Carex appropinquata | Fibrous Tussock-sedge | Yes | A1 | 152--16--2 | N | Schumach. | 0920000342 |
| Carex aquatilis | Water Sedge | Yes | A1 | 152--16--64 | N | Wahlenb. | 0920000343 |
| Carex aquatilis x acuta | Yes S2 | A1 | 152--16--64 x 65 | ||||
| Carex aquatilis x bigelowii = C. x limula | Yes | A1 | 152--16--64 x 69 | Fr. | 0920002604 | ||
| Carex aquatilis x nigra = C. x hibernica | Yes | A1 | 152--16--64 x 67 | A. Benn. | 0920002602 | ||
| Carex arenaria | Sand Sedge | Page 15 | A1 | 152--16--10 | N | L. | 0920000344 |
| Carex atrata | Black Alpine-sedge | Yes | A1 | 152--16--60 | N | L. | 0920000345 |
| Carex atrofusca | Scorched Alpine-sedge | Yes | A1 | 152--16--56 | N | Schkuhr | 0920000346 |
| Carex bicolor | Bicoloured Sedge | Clement | A3 | 152--16--bic | All. | 0920000348 | |
| Carex bigelowii | Stiff Sedge | Yes | A1 | 152--16--69 | N | Torr. ex Schwein. | 0920000349 |
| Carex binervis | Green-ribbed Sedge | Page 15 | A1 | 152--16--40 | N | Sm. | 0920000350 |
| Carex binervis x punctata | Yes | A1 | 152--16--40 x 42 | 0920002885 | |||
| Carex binervis x viridula = C. x corstorphinei | Yes | A1 | 152--16--40 x 46 | Druce | 0920007210 | ||
| Carex brunnea | Clement | A3 | 152--16--bru | Thunb. | 0920006066 | ||
| Carex buchananii | Silver-spiked Sedge | Yes S1 | A1 | 152--16--buc | Ne | Berggr. | 0920003328 |
| Carex buxbaumii | Club Sedge | Yes | A1 | 152--16--61 | N | Wahlenb. | 0920000352 |
| Carex capillaris | Hair Sedge | Yes | A1 | 152--16--33 | N | L. | 0920000353 |
| Carex capitata | Clement | A3 | 152--16--cap | L. | 0920000354 | ||
| Carex caryophyllea | Spring-sedge | Page 15 | A1 | 152--16--51 | N | Latourr. | 0920000355 |
| Carex chordorrhiza | String Sedge | Yes | A1 | 152--16--12 | N | L. f. | 0920000356 |
| Carex crawfordii | Crawford's Sedge | Clement | A3 | 152--16--cra | Fernald | 0920000358 | |
| Carex curta | White Sedge | Yes | A1 | 152--16--22 | N | Gooden. | 0920000359 |
| Carex davalliana | Davall's Sedge | Yes | A1 | 152--16--19 | N | Sm. | 0920000360 |
| Carex depauperata | Starved Wood-sedge | Yes | A1 | 152--16--38 | N | Curtis ex With. | 0920000362 |
| Carex devia | Clement | A3 | 152--16--dev | Cheeseman | 0920006067 | ||
| Carex deweyana | Clement | A3 | 152--16--dew | Schwein. | 0920006068 | ||
| Carex diandra | Lesser Tussock-sedge | Yes | A1 | 152--16--3 | N | Schrank | 0920000363 |
| Carex digitata | Fingered Sedge | Yes | A1 | 152--16--48 | N | L. | 0920000364 |
| Carex dioica | Dioecious Sedge | Page 15 | A1 | 152--16--18 | N | L. | 0920000365 |
| Carex distans | Distant Sedge | Page 15 | A1 | 152--16--41 | N | L. | 0920000366 |
| Carex distans x extensa = C. x tornabenii | Yes | A1 | 152--16--41 x 43 | Chiov. | 0920002884 | ||
| Carex distans x hostiana = C. x muelleriana | Yes | A1 | 152--16--41 x 44 | F.W. Schultz | 0920002883 | ||
| Carex distans x viridula = C. x luteola | Yes | A1 | 152--16--41 x 46 | Sendtn. | 0920007209 | ||
| Carex disticha | Brown Sedge | Page 15 | A1 | 152--16--11 | N | Huds. | 0920000367 |
| Carex divisa | Divided Sedge | Page 15 | A1 | 152--16--13 | N | Huds. | 0920000368 |
| Carex divulsa | Yes | A1 | 152--16--9 | Stokes | 0920004520 | ||
| Carex divulsa subsp. divulsa | Grey Sedge | Yes | A1 | 152--16--9--a | N | 0920000369 | |
| Carex divulsa subsp. leersii | Many-leaved Sedge | Yes | A1 | 152--16--9--b | N | (Kneuck.) W. Koch | 0920000406 |
| Carex divulsa x remota = C. x emmae | Yes | A1 | 152--16--9 x 15 | L. Gross | 0920002893 | ||
| Carex echinata | Star Sedge | Page 15 | A1 | 152--16--17 | N | Murray | 0920000370 |
| Carex echinata x curta = C. x biharica | Yes | A1 | 152--16--17 x 22 | Simonk. | 0920002599 | ||
| Carex echinata x dioica = C. x gaudiniana | Yes | A1 | 152--16--17 x 18 | Guthnick | 0920002894 | ||
| Carex elata | Tufted-sedge | Yes | A1 | 152--16--68 | N | All. | 0920000371 |
| Carex elongata | Elongated Sedge | Yes | A1 | 152--16--20 | N | L. | 0920000372 |
| Carex ericetorum | Rare Spring-sedge | Yes | A1 | 152--16--53 | N | Pollich | 0920000373 |
| Carex extensa | Long-bracted Sedge | Page 15 | A1 | 152--16--43 | N | Gooden. | 0920000374 |
| Carex filiformis | Downy-fruited Sedge | Yes | A1 | 152--16--52 | N | L. | 0920000375 |
| Carex flacca | Glaucous Sedge | Page 15 | A1 | 152--16--35 | N | Schreb. | 0920000376 |
| Carex flagellifera | Clement | A3 | 152--16--fla | Colenso | 0920006069 | ||
| Carex flava | Large Yellow-sedge | Yes | A1 | 152--16--45 | N | L. | 0920000378 |
| Carex flava x viridula = C. x alsatica | Yes | A1 | 152--16--45 x 46 | Zahn | 0920007208 | ||
| Carex glacialis | Clement | A3 | 152--16--gla | Mack. | 0920000379 | ||
| Carex hirta | Hairy Sedge | Page 15 | A1 | 152--16--23 | N | L. | 0920000381 |
| Carex hirta x vesicaria = C. x grossii | Yes | A1 | 152--16--23 x 29 | Fiek | 0920002888 | ||
| Carex hostiana | Tawny Sedge | Page 15 | A1 | 152--16--44 | N | DC. | 0920000382 |
| Carex hostiana x viridula = C. x fulva | Yes | A1 | 152--16--44 x 46 | N | Gooden. | 0920002609 | |
| Carex hubbardii | Clement | A3 | 152--16--hub | Nelmes | 0920006070 | ||
| Carex humilis | Dwarf Sedge | Yes | A1 | 152--16--50 | N | Leyss. | 0920000383 |
| Carex inversa | Knob Sedge | Clement | A3 | 152--16--inv | R. Br. | 0920006071 | |
| Carex lachenalii | Hare's-foot Sedge | Yes | A1 | 152--16--21 | N | Schkuhr | 0920000384 |
| Carex lachenalii x curta = C. x helvola | Yes | A1 | 152--16--21 x 22 | Blytt ex Fr. | 0920002895 | ||
| Carex laevigata | Smooth-stalked Sedge | Yes | A1 | 152--16--39 | N | Sm. | 0920000385 |
| Carex laevigata x binervis = C. x deserta | Yes | A1 | 152--16--39 x 40 | Merino | 0920002881 | ||
| Carex laevigata x viridula | Yes | A1 | 152--16--39 x 46 | 0920007207 | |||
| Carex lasiocarpa | Slender Sedge | Yes | A1 | 152--16--24 | N | Ehrh. | 0920000386 |
| Carex lasiocarpa x riparia = C. x evoluta | Yes | A1 | 152--16--24 x 26 | Hartm. | 0920002889 | ||
| Carex limosa | Bog-sedge | Yes | A1 | 152--16--57 | N | L. | 0920000388 |
| Carex longebrachiata | Drooping Sedge | Clement | A3 | 152--16--lon | Boeck. | 0920006072 | |
| Carex magellanica | Tall Bog-sedge | Yes | A1 | 152--16--59 | N | Lam. | 0920000403 |
| Carex magellanica subsp. irrigua | Yes | A1 | 152--16--59--a | (Wahlenb.) Hiitonen | 0920000403 | ||
| Carex maritima | Curved Sedge | Yes | A1 | 152--16--14 | N | Gunnerus | 0920000389 |
| Carex microglochin | Bristle Sedge | Yes | A1 | 152--16--70 | N | Wahlenb. | 0920000390 |
| Carex montana | Soft-leaved Sedge | Yes | A1 | 152--16--54 | N | L. | 0920000391 |
| Carex muricata | Page 15 | A1 | 152--16--8 | L. | 0920000398 | ||
| Carex muricata subsp. muricata | Large-fruited Prickly-sedge | Yes | A1 | 152--16--8--a | N | 0920000398.1 | |
| Carex muricata subsp. pairae | Small-fruited Prickly-sedge | Yes S3 | A1 | 152--16--8--b | N | (F.W. Schultz) Celak. | 0920000398.2 |
| Carex muricata x divulsa | Yes S1 | A1 | 152--16--8 x 9 | 0920007905 | |||
| Carex nigra | Common Sedge | Page 15 | A1 | 152--16--67 | N | (L.) Reichard | 0920000393 |
| Carex nigra x bigelowii = C. x decolorans | Yes | A1 | 152--16--67 x 69 | Wimm. | 0920002600 | ||
| Carex nigra x elata = C. x turfosa | Yes | A1 | 152--16--67 x 68 | Fr. | 0920002607 | ||
| Carex norvegica | Close-headed Alpine-sedge | Yes | A1 | 152--16--62 | N | Retz. | 0920000394 |
| Carex ornithopoda | Bird's-foot Sedge | Yes | A1 | 152--16--49 | N | Willd. | 0920000395 |
| Carex otrubae | False Fox-sedge | Page 15 | A1 | 152--16--5 | N | Podp. | 0920000396 |
| Carex otrubae x divulsa | Yes | A1 | 152--16--5 x 9 | 0920007206 | |||
| Carex otrubae x remota = C. x pseudoaxillaris | Yes | A1 | 152--16--5 x 15 | N | K. Richt. | 0920000347 | |
| Carex ovalis | Oval Sedge | Page 15 | A1 | 152--16--16 | N | Gooden. | 0920000397 |
| Carex pallescens | Pale Sedge | Page 15 | A1 | 152--16--47 | N | L. | 0920000399 |
| Carex panicea | Carnation Sedge | Page 15 | A1 | 152--16--36 | N | L. | 0920000400 |
| Carex paniculata | Greater Tussock-sedge | Page 15 | A1 | 152--16--1 | N | L. | 0920000401 |
| Carex paniculata x appropinquata = C. x rotae | Yes | A1 | 152--16--1 x 2 | De Not. | 0920002892 | ||
| Carex paniculata x curta = C. x ludibunda | Yes | A1 | 152--16--1 x 22 | J. Gay | 0920007212 | ||
| Carex paniculata x diandra = C. x beckmannii | Yes | A1 | 152--16--1 x 3 | Keck ex F.W. Schultz | 0920004348 | ||
| Carex paniculata x remota = C. x boenninghauseniana | Yes | A1 | 152--16--1 x 15 | N | Weihe | 0920000351 | |
| Carex pauciflora | Few-flowered Sedge | Yes | A1 | 152--16--71 | N | Lightf. | 0920000402 |
| Carex pendula | Pendulous Sedge | Page 17 | A1 | 152--16--31 | N | Huds. | 0920000404 |
| Carex pilulifera | Pill Sedge | Page 17 | A1 | 152--16--55 | N | L. | 0920000405 |
| Carex pseudocyperus | Cyperus Sedge | Page 17 | A1 | 152--16--27 | N | L. | 0920000407 |
| Carex pseudocyperus x rostrata = C. x justi-schmidtii | Yes | A1 | 152--16--27 x 28 | Junge | 0920002886 | ||
| Carex pulicaris | Flea Sedge | Page 17 | A1 | 152--16--73 | N | L. | 0920000408 |
| Carex punctata | Dotted Sedge | Yes | A1 | 152--16--42 | N | Gaudin | 0920000409 |
| Carex rariflora | Mountain Bog-sedge | Yes | A1 | 152--16--58 | N | (Wahlenb.) Sm. | 0920000410 |
| Carex recta | Estuarine Sedge | Yes | A1 | 152--16--63 | N | Boott | 0920000411 |
| Carex recta x aquatilis = C. x grantii | Yes | A1 | 152--16--63 x 64 | A. Benn. | 0920002891 | ||
| Carex remota | Remote Sedge | Page 17 | A1 | 152--16--15 | N | L. | 0920000412 |
| Carex riparia | Greater Pond-sedge | Page 17 | A1 | 152--16--26 | N | Curtis | 0920000413 |
| Carex riparia x vesicaria = C. x csomadensis | Yes | A1 | 152--16--26 x 29 | Simonk. | 0920002887 | ||
| Carex rostrata | Bottle Sedge | Page 17 | A1 | 152--16--28 | N | Stokes | 0920000414 |
| Carex rostrata x vesicaria = C. x involuta | Yes | A1 | 152--16--28 x 29 | N | (Bab.) Syme | 0920002603 | |
| Carex rupestris | Rock Sedge | Yes | A1 | 152--16--72 | N | Bellardi ex All. | 0920000415 |
| Carex salina | Saltmarsh Sedge | Yes S3 | A1 | 152--16--sal | N | Wahlenb. | |
| Carex saxatilis | Russet Sedge | Yes | A1 | 152--16--30 | N | L. | 0920000417 |
| Carex saxatilis x viridula | Yes S3 | A1 | 152--16--30 x 46 | N | |||
| Carex secta | Clement | A3 | 152--16--sec | Boott | 0920006073 | ||
| Carex solandri | Clement | A3 | 152--16--sol | Boott | 0920006074 | ||
| Carex spicata | Spiked Sedge | Page 17 | A1 | 152--16--7 | N | Huds. | 0920000357 |
| Carex strigosa | Thin-spiked Wood-sedge | Yes | A1 | 152--16--34 | N | Huds. | 0920000420 |
| Carex sylvatica | Wood-sedge | Page 17 | A1 | 152--16--32 | N | Huds. | 0920000421 |
| Carex tereticaulis | Clement | A3 | 152--16--ter | F. Muell. | 0920006075 | ||
| Carex trinervis | Three-nerved Sedge | Yes | A1 | 152--16--66 | N | Degl. | 0920000422 |
| Carex vaginata | Sheathed Sedge | Yes | A1 | 152--16--37 | N | Tausch | 0920000423 |
| Carex vesicaria | Bladder-sedge | Page 17 | A1 | 152--16--29 | N | L. | 0920000424 |
| Carex vesicaria x saxatilis = C. x grahamii | Mountain Bladder-sedge | Yes | A1 | 152--16--29 x 30 | Boott | 0920000380 | |
| Carex virgata | Clement | A3 | 152--16--vir | Sol. ex Boott | 0920006076 | ||
| Carex viridula | Page 17 | A1 | 152--16--46 | Michx. | 0920007117 | ||
| Carex viridula subsp. brachyrrhyncha | Long-stalked Yellow-sedge | Yes | A1 | 152--16--46--a | N | (Celak.) B. Schmid | 0920000387 |
| Carex viridula subsp. oedocarpa | Common Yellow-sedge | Yes | A1 | 152--16--46--b | N | (Andersson) B. Schmid | 0920000361 |
| Carex viridula subsp. viridula | Small-fruited Yellow-sedge | Yes | A1 | 152--16--46--c | N | 0920007118 | |
| Carex vulpina | True Fox-sedge | Yes | A1 | 152--16--4 | N | L. | 0920000425 |
| Carex vulpinoidea | American Fox-sedge | Yes | A1 | 152--16--6 | Ne | Michx. | 0920000426 |
| Carlina acaulis | Clement | A3 | 135--2--aca | L. | 0920006077 | ||
| Carlina vulgaris | Carline Thistle | Page 17 | A1 | 135--2--1 | N | L. | 0920000427 |
| Carpinus betulus | Hornbeam | Page 17 | A1 | 40--3--1 | N | L. | 0920000428 |
| Carpobrotus acinaciformis | Sally-my-handsome | Yes | A1 | 42--8--1 | Ne | (L.) L. Bolus | 0920007213 |
| Carpobrotus edulis | Hottentot-fig | Page 17 | A1 | 42--8--2 | Ne | (L.) N.E. Br. | 0920000429 |
| Carpobrotus glaucescens | Angular Sea-fig | Yes | A1 | 42--8--3 | Ne | (Haw.) Schwantes | 0920002386 |
| Carrichtera annua | Cress Rocket | Clement | A3 | 62--CAR--ann | (L.) DC. | 0920004354 | |
| Carthamus dentatus | Clement | A3 | 135--CAR--den | (Forssk.) J. Vahl | 0920006078 | ||
| Carthamus lanatus | Downy Safflower | Stace | A2 | 135--CAR--lan | Ca | L. | 0920007988 |
| Carthamus oxyacanthus | Clement | A3 | 135--CAR--oxy | M. Bieb. | 0920006079 | ||
| Carthamus tenuis | Clement | A3 | 135--CAR--ten | (Boiss. & Blanchet) Bornm. | 0920006080 | ||
| Carthamus tinctorius | Safflower | Clement | A2 | 135--CAR--tin | Ca | L. | 0920004424 |
| Carum carvi | Caraway | Yes | A1 | 107--34--1 | Ar | L. | 0920000430 |
| Carum verticillatum | Whorled Caraway | Page 17 | A1 | 107--34--2 | N | (L.) W.D.J. Koch | 0920000431 |
| Carya cordiformis | Bitternut Hickory | Clement | A3 | 37--CAR--cor | (Wangenh.) K. Koch | 0920006081 | |
| Carya ovata | Shagbark Hickory | Clement | A3 | 37--CAR--ova | (Poir.) Spach | 0920006082 | |
| Caryopteris incana x mongholica = C. x clandonensis | Bluebeard | Clement | A3 | 117--CAR--inc x mon | A. Simmonds ex Rehder | 0920006083 | |
| Cassia fistula | Purging Cassia | Clement | A3 | 76A--CAS--fis | L. | 0920006084 | |
| Cassinia fulvida | Golden-bush | Clement | A3 | 135--CAS--ful | Hook. f. | 0920004094 | |
| Castanea crenata | Japanese Chestnut | Clement | A3 | 39--3--cre | Siebold & Zucc. | 0920006085 | |
| Castanea sativa | Sweet Chestnut | Page 17 | A1 | 39--3--1 | Ar | Mill. | 0920000432 |
| Castellia tuberculosa | Clement | A3 | 153--CAS--tub | (Moris) Bor | 0920006086 | ||
| Castilleja coccinea | Clement | A3 | 124--CAS--coc | (L.) Spreng. | 0920006087 | ||
| Catabrosa aquatica | Whorl-grass | Page 17 | A1 | 153--20--1 | N | (L.) P. Beauv. | 0920000433 |
| Catalpa bignonioides | Indian-bean-tree | Clement | A3 | 127B--CAT--big | Walter | 0920004179 | |
| Catananche caerulea | Blue Cupidone | Yes S1 | A1 | 135--CAT--cae | Ne | L. | 0920003329 |
| Catapodium marinum | Sea Fern-grass | Page 17 | A1 | 153--21--2 | N | (L.) C.E. Hubb. | 0920000434 |
| Catapodium rigidum | Fern-grass | Page 17 | A1 | 153--21--1 | N | (L.) C.E. Hubb. | 0920000435 |
| Catapodium rigidum subsp. hemipoa | Clement | A3 | 153--21--1--b | (Delile ex Spreng.) Stace | 0920000435.3 | ||
| Catapodium rigidum x marinum | Yes | A1 | 153--21--1 x 2 | 0920007214 | |||
| Caucalis bischoffii | Clement | A3 | 107--CAU--bis | Kozo-Pol. | 0920006089 | ||
| Caucalis platycarpos | Small Bur-parsley | Clement | A3 | 107--CAU--pla | L. | 0920000436 | |
| Caulophyllum thalictroides | Blue Cohosh | Clement | A3 | 29--CAU--tha | Michx. | 0920006090 | |
| Caylusea hexagyna | Clement | A3 | 63--CAY--hex | (Forssk.) M.L. Green | 0920006091 | ||
| Cedronella canariensis | Canary Islands Balm | Clement | A3 | 118--CED--can | (L.) Webb & Berthel. | 0920006092 | |
| Cedrus atlantica | Atlas Cedar | Yes | A1 | 20--6--2 | Ne | (Endl.) CarriŠre | 0920002978 |
| Cedrus deodara | Deodar | Yes | A1 | 20--6--1 | Ne | (Roxb. ex D. Don) G. Don | 0920002413 |
| Cedrus libani | Cedar-of-Lebanon | Stace | A2 | 20--6--lib | Ne | A. Rich. | 0920006789 |
| Celastrus orbiculatus | Staff-vine | Yes S1 | A1 | 88--CEL--orb | Ne | Thunb. | 0920003333 |
| Celosia cristata | Clement | A3 | 44--CEL--cri | L. | 0920006093 | ||
| Celosia trigyna | Clement | A3 | 44--CEL--tri | L. | 0920006094 | ||
| Cenchrus ciliaris | Buffel-grass | Clement | A3 | 153--CEN--cil | L. | 0920006095 | |
| Cenchrus echinatus | Spiny Sandbur | Stace | A2 | 153--CEN--ech | Ca | L. | 0920003298 |
| Cenchrus incertus | Clement | A3 | 153--CEN--inc | M.A. Curtis | 0920006096 | ||
| Cenchrus longispinus | Clement | A3 | 153--CEN--lon | (Hack.) Fernald | 0920004264 | ||
| Cenchrus pennisetiformis | Clement | A3 | 153--CEN--pen | Hochst. & Steud. ex Steud. | 0920006097 | ||
| Cenchrus setigerus | Clement | A3 | 153--CEN--set | Vahl | 0920006098 | ||
| Centaurea apiculata | Clement | A3 | 135--11--api | Ledeb. | 0920006099 | ||
| Centaurea aspera | Rough Star-thistle | Yes | A1 | 135--11--5 | Ne | L. | 0920000438 |
| Centaurea atropurpurea | Clement | A3 | 135--11--atr | Waldst. & Kit. | 0920006100 | ||
| Centaurea bruguieriana | Clement | A3 | 135--11--bru | (DC.) Hand.-Mazz. | 0920006101 | ||
| Centaurea calcitrapa | Red Star-thistle | Yes | A1 | 135--11--4 | Ar | L. | 0920000439 |
| Centaurea centauroides | Clement | A3 | 135--11--cen | L. | 0920006102 | ||
| Centaurea cheiranthifolia | Clement | A3 | 135--11--che | Willd. | 0920006103 | ||
| Centaurea cineraria | Clement | A3 | 135--11--cin | L. | 0920006104 | ||
| Centaurea cyanus | Cornflower | Yes | A1 | 135--11--3 | Ar | L. | 0920000440 |
| Centaurea dalmatica | Clement | A3 | 135--11--dal | A. Kern. | 0920006105 | ||
| Centaurea dealbata | Clement | A3 | 135--11--dea | Willd. | 0920006106 | ||
| Centaurea debeauxii | Slender Knapweed | Yes S2 | A1 | 135--11--deb | Gren. & Godr. | ||
| Centaurea debeauxii subsp. nemoralis | Yes S2 | A1 | 135--11--deb--a | (Jord.) Dost l | |||
| Centaurea depressa | Clement | A3 | 135--11--dep | M. Bieb. | 0920006107 | ||
| Centaurea diffusa | Clement | A3 | 135--11--dif | Lam. | 0920004203 | ||
| Centaurea diluta | Lesser Star-thistle | Stace | A2 | 135--11--dil | Ca | Aiton | 0920002421 |
| Centaurea eriophora | Clement | A3 | 135--11--eri | L. | 0920006108 | ||
| Centaurea hyalolepis | Clement | A3 | 135--11--hya | Boiss. | 0920005604 | ||
| Centaurea iberica | Iberian Star-thistle | Clement | A3 | 135--11--ibe | Trevir. ex Spreng. | 0920005603 | |
| Centaurea intybacea | Clement | A3 | 135--11--int | Lam. | 0920006109 | ||
| Centaurea jacea | Brown Knapweed | Yes S2 | A1 | 135--11--jac | L. | 0920000441 | |
| Centaurea leucophaea | Whitish-leaved Knapweed | Clement | A3 | 135--11--leu | Jord. | 0920006110 | |
| Centaurea macrocephala | Giant Knapweed | Yes S1 | A1 | 135--11--mac | Ne | Muss. Puschk. ex Willd. | 0920003334 |
| Centaurea maculosa | Spotted Knapweed | Clement | A3 | 135--11--mal | Lam. | 0920005624 | |
| Centaurea melitensis | Maltese Star-thistle | Stace | A2 | 135--11--mel | Ca | L. | 0920000443 |
| Centaurea montana | Perennial Cornflower | Yes | A1 | 135--11--2 | Ne | L. | 0920002422 |
| Centaurea napifolia | Clement | A3 | 135--11--nap | L. | 0920006111 | ||
| Centaurea nicaeensis | Clement | A3 | 135--11--nic | All. | 0920006112 | ||
| Centaurea nigra | Common Knapweed | Page 17 | A1 | 135--11--7 | N | L. | 0920000444 |
| Centaurea nigra x jacea = C. x moncktonii | Hybrid Knapweed | Yes S1 | A1 | 135--11--7 x jac | C.E. Britton | 0920000442 | |
| Centaurea orientalis | Clement | A3 | 135--11--ori | L. | 0920005625 | ||
| Centaurea paniculata | Jersey Knapweed | Clement | A3 | 135--11--pan | L. | 0920000445 | |
| Centaurea patula | Clement | A3 | 135--11--pat | DC. | 0920006113 | ||
| Centaurea pullata | Clement | A3 | 135--11--pul | L. | 0920006114 | ||
| Centaurea rhenana | Panicled Knapweed | Clement | A3 | 135--11--rhe | Boreau | 0920005626 | |
| Centaurea scabiosa | Greater Knapweed | Page 19 | A1 | 135--11--1 | N | L. | 0920000446 |
| Centaurea solstitialis | Yellow Star-thistle | Yes | A1 | 135--11--6 | Ne | L. | 0920000447 |
| Centaurea spinosa | Clement | A3 | 135--11--spi | L. | 0920005623 | ||
| Centaurea stenolepis | Clement | A3 | 135--11--ste | A. Kern. | 0920006115 | ||
| Centaurea trichocephala | Clement | A3 | 135--11--trc | M. Bieb. ex Willd. | 0920005627 | ||
| Centaurea triumfetti | Clement | A3 | 135--11--tri | All. | 0920006116 | ||
| Centaurea verutum | Clement | A3 | 135--11--ver | L. | 0920004204 | ||
| Centaurium erythraea | Common Centaury | Page 19 | A1 | 108--3--2 | N | Rafn | 0920005486 |
| Centaurium erythraea x littorale = C. x intermedium | Yes | A1 | 108--3--2 x 3 | (Wheldon) Druce | 0920002804 | ||
| Centaurium erythraea x pulchellum | Yes | A1 | 108--3--2 x 4 | 0920002803 | |||
| Centaurium littorale | Seaside Centaury | Yes | A1 | 108--3--3 | N | (Turner ex Sm.) Gilmour | 0920000450 |
| Centaurium pulchellum | Lesser Centaury | Yes | A1 | 108--3--4 | N | (Sw.) Druce | 0920000453 |
| Centaurium scilloides | Perennial Centaury | Yes | A1 | 108--3--1 | N | (L. f.) Samp. | 0920000452 |
| Centaurium tenuiflorum | Slender Centaury | Yes | A1 | 108--3--5 | N | (Hoffmanns. & Link) Fritsch | 0920000454 |
| Centipeda minima | Spreading Sneezeweed | Clement | A3 | 135--CEN--min | (L.) A. Braun & Asch. | 0920006117 | |
| Centranthus calcitrapae | Annual Valerian | Yes | A1 | 133--3--2 | Ne | (L.) Dufr. | 0920007215 |
| Centranthus macrosiphon | Spanish Valerian | Clement | A3 | 133--3--mac | (L.) Dufr. | 0920006118 | |
| Centranthus ruber | Red Valerian | Page 19 | A1 | 133--3--1 | Ne | (L.) DC. | 0920000455 |
| Cephalanthera damasonium | White Helleborine | Page 17 | A1 | 162--2--1 | N | (Mill.) Druce | 0920000457 |
| Cephalanthera damasonium x longifolia = C. x schulzei | Yes | A1 | 162--2--1 x 2 | E.G. Camus, Bergon & A. Camus | 0920007216 | ||
| Cephalanthera longifolia | Narrow-leaved Helleborine | Yes | A1 | 162--2--2 | N | (L.) Fritsch | 0920000458 |
| Cephalanthera rubra | Red Helleborine | Yes | A1 | 162--2--3 | N | (L.) Rich. | 0920000459 |
| Cephalaria alpina | Alpine Scabious | Clement | A3 | 134--2--alp | (Lag.) Roem. & Schult. | 0920006119 | |
| Cephalaria gigantea | Giant Scabious | Yes | A1 | 134--2--1 | Ne | (Ledeb.) Bobrov | 0920004425 |
| Cephalaria syriaca | Clement | A3 | 134--2--syr | (L.) Schrad. | 0920005605 | ||
| Cephalaria transylvanica | Clement | A3 | 134--2--tra | (L.) Roem. & Schult. | 0920005606 | ||
| Cephalotaxus fortunei | Chinese Plum-yew | Clement | A3 | 21A--CEP--for | Hook. | 0920003611 | |
| Cephalotaxus harringtonia | Japanese Plum-yew | Clement | A3 | 21A--CEP--har | (T. Knight ex Forbes) K. Koch | 0920003613 | |
| Cerastium alpinum | Alpine Mouse-ear | Yes | A1 | 46--7--4 | N | L. | 0920000460 |
| Cerastium alpinum subsp. lanatum | Yes | A1 | 46--7--4--a | (Lam.) Ces. | 0920000460 | ||
| Cerastium alpinum x fontanum = C. x symei | Yes | A1 | 46--7--4 x 7 | Druce | 0920002693 | ||
| Cerastium alpinum x nigrescens | Yes S3 | A1 | 46--7--4 x 6 | 0920002692 | |||
| Cerastium arvense | Field Mouse-ear | Page 19 | A1 | 46--7--2 | N | L. | 0920000461 |
| Cerastium arvense x fontanum = C. x pseudoalpinum | Yes | A1 | 46--7--2 x 7 | Murr | 0920002691 | ||
| Cerastium arvense x tomentosum | Yes | A1 | 46--7--2 x 3 | 0920005389 | |||
| Cerastium brachypetalum | Grey Mouse-ear | Yes | A1 | 46--7--9 | Ne | Pers. | 0920000463 |
| Cerastium cerastoides | Starwort Mouse-ear | Yes | A1 | 46--7--1 | N | (L.) Britton | 0920000464 |
| Cerastium dichotomum | Clement | A3 | 46--7--dic | L. | 0920006120 | ||
| Cerastium diffusum | Sea Mouse-ear | Page 19 | A1 | 46--7--10 | N | Pers. | 0920000462 |
| Cerastium fontanum | Common Mouse-ear | Page 19 | A1 | 46--7--7 | N | Baumg. | 0920000467 |
| Cerastium fontanum subsp. holosteoides | Yes | A1 | 46--7--7--b | (Fr.) Salman, Ommering & de Voogd | 0920000467.3 | ||
| Cerastium fontanum subsp. scoticum | Yes | A1 | 46--7--7--c | N | Jalas & P.D. Sell | 0920000467.2 | |
| Cerastium fontanum subsp. vulgare | Yes | A1 | 46--7--7--a | (Hartm.) Greuter & Burdet | 0920000467.1 | ||
| Cerastium glomeratum | Sticky Mouse-ear | Page 19 | A1 | 46--7--8 | N | Thuill. | 0920000466 |
| Cerastium ligusticum | Clement | A3 | 46--7--lig | Viv. | 0920006121 | ||
| Cerastium nigrescens | Arctic Mouse-ear | Yes S3 | A1 | 46--7--6 | N | (H.C. Watson) Edmondston ex H.C. Watson | 0920000465.1 |
| Cerastium nigrescens x fontanum = C. x richardsonii | Yes | A1 | 46--7--6 x 7 | Druce | 0920002694 | ||
| Cerastium pumilum | Dwarf Mouse-ear | Yes | A1 | 46--7--11 | N | Curtis | 0920000468 |
| Cerastium scaranii | Italian Mouse-ear | Clement | A3 | 46--7--sca | Ten. | 0920006122 | |
| Cerastium semidecandrum | Little Mouse-ear | Page 19 | A1 | 46--7--12 | N | L. | 0920000469 |
| Cerastium tomentosum | Snow-in-summer | Page 19 | A1 | 46--7--3 | Ne | L. | 0920000470 |
| Ceratocapnos claviculata | Climbing Corydalis | Page 19 | A1 | 31--4--1 | N | (L.) Lid‚n | 0920000555 |
| Ceratocephala falcata | Clement | A3 | 28--CER--fal | (L.) Pers. | 0920005615 | ||
| Ceratocephala testiculata | Clement | A3 | 28--CER--tes | (Crantz) Roth | 0920006123 | ||
| Ceratochloa brevis | Patagonian Brome | Stace | A2 | 153--53--bre | Ca | (Nees ex Steud.) B.D. Jacks. | 0920003095 |
| Ceratochloa carinata | California Brome | Yes | A1 | 153--53--1 | Ne | (Hook. & Arn.) Tutin | 0920000260 |
| Ceratochloa cathartica | Rescue Brome | Yes | A1 | 153--53--3 | Ne | (Vahl) Herter | 0920000261 |
| Ceratochloa marginata | Western Brome | Yes | A1 | 153--53--2 | Ne | (Nees ex Steud.) B.D. Jacks. | 0920007217 |
| Ceratochloa staminea | Southern Brome | Clement | A3 | 153--53--sta | Ne | (Desv.) Stace | 0920003073 |
| Ceratonia siliqua | Carob | Clement | A3 | 76A--CET--sil | L. | 0920006124 | |
| Ceratophyllum demersum | Rigid Hornwort | Page 19 | A1 | 27--1--1 | N | L. | 0920000471 |
| Ceratophyllum submersum | Soft Hornwort | Yes | A1 | 27--1--2 | N | L. | 0920000472 |
| Ceratostigma plumbaginoides | Clement | A3 | 48--CER--plu | Bunge | 0920004142 | ||
| Cercis siliquastrum | Judas-tree | Clement | A3 | 76A--CER--sil | L. | 0920004047 | |
| Cerinthe glabra | Smooth Honeywort | Clement | A3 | 116--CER--gla | Mill. | 0920006125 | |
| Cerinthe major | Greater Honeywort | Clement | A3 | 116--CER--maj | L. | 0920005672 | |
| Cerinthe minor | Lesser Honeywort | Clement | A3 | 116--CER--min | L. | 0920006126 | |
| Ceterach officinarum | Rustyback | Page 19 | A1 | 15--3--1 | N | Willd. | 0910000473 |
| Chaenomeles cathayensis | Clement | A3 | 75--25--cat | (Hemsl.) C.K. Schneid. | 0920006127 | ||
| Chaenomeles japonica | Japanese Quince | Yes S1 | A1 | 75--25--jap | Ne | (Thunb.) Spach | 0920003335 |
| Chaenomeles speciosa | Japanese Quince | Yes | A1 | 75--25--1 | Ne | (Sweet) Nakai | 0920007218 |
| Chaenomeles speciosa x japonica = C. x superba | Clement | A3 | 75--25--1 x jap | (Frahm) Rehder | 0920006129 | ||
| Chaenomeles x superba x cathayensis = C. x californica | Clement | A3 | 75--25--1 x jap x cat | W.B. Clarke ex J.G.C. Weber | 0920006128 | ||
| Chaenorhinum minus | Small Toadflax | Page 19 | A1 | 124--8--2 | Ar | (L.) Lange | 0920000474 |
| Chaenorhinum origanifolium | Malling Toadflax | Yes | A1 | 124--8--1 | Ne | (L.) Kostel. | 0920007219 |
| Chaenorhinum rubrifolium | Clement | A3 | 124--8--rub | (Robill. & Castagne ex DC.) Fourr. | 0920006130 | ||
| Chaerophyllum aromaticum | Broad-leaved Chervil | Clement | A3 | 107--5--aro | L. | 0920006131 | |
| Chaerophyllum aureum | Golden Chervil | Yes | A1 | 107--5--2 | Ne | L. | 0920000475 |
| Chaerophyllum hirsutum | Hairy Chervil | Yes | A1 | 107--5--1 | Ne | L. | 0920007220 |
| Chaerophyllum temulum | Rough Chervil | Page 19 | A1 | 107--5--3 | N | L. | 0920000476 |
| Chaetosciadium trichospermum | Clement | A3 | 107--CHA--tri | (L.) Boiss. | 0920006132 | ||
| Chamaecrista nictitans | Sensitive Cassia | Clement | A3 | 76A--CHA--nic | (L.) Moench | 0920006133 | |
| Chamaecyparis lawsoniana | Lawson's Cypress | Yes | A1 | 21--2--1 | Ne | (A. Murray bis) Parl. | 0920002398 |
| Chamaecyparis obtusa | Hinoki Cypress | Clement | A3 | 21--2--obt | (Siebold & Zucc.) Endl. | 0920002969 | |
| Chamaecyparis pisifera | Sawara Cypress | Yes | A1 | 21--2--2 | Ne | (Siebold & Zucc.) Siebold & Zucc. | 0920002970 |
| Chamaecytisus purpureus | Purple Broom | Clement | A3 | 77--CHA--pur | (Scop.) Link | 0920006134 | |
| Chamaecytisus supinus | Clustered Broom | Clement | A3 | 77--CHA--sup | (L.) Link | 0920006135 | |
| Chamaemelum mixtum | Clement | A3 | 135--54--mix | (L.) All. | 0920004086 | ||
| Chamaemelum nobile | Chamomile | Page 19 | A1 | 135--54--1 | N | (L.) All. | 0920000119 |
| Chamerion angustifolium | Rosebay Willowherb | Page 19 | A1 | 84--2--1 | N | (L.) Holub | 0920000477 |
| Chamorchis alpina | False Orchid | Clement | A3 | 162--CHA--alp | (L.) Rich. | 0920006136 | |
| Chasmanthe bicolor | Chasmanthe | Yes | A1 | 159--14--1 | Ne | (Gasp. ex Ten.) N.E. Br. | 0920007221 |
| Chasmanthium latifolium | Clement | A3 | 153--CHA--lat | (Michx.) Link | 0920005673 | ||
| Chelidonium majus | Greater Celandine | Page 19 | A1 | 30--5--1 | Ar | L. | 0920000480 |
| Chenopodium acuminatum | Clement | A3 | 43--1--acu | Willd. | 0920006137 | ||
| Chenopodium album | Fat-hen | Page 19 | A1 | 43--1--15 | N | L. | 0920000482 |
| Chenopodium ambrosioides | Mexican-tea | Yes | A1 | 43--1--1 | Ne | L. | 0920007222 |
| Chenopodium antarcticum | Clement | A3 | 43--1--ant | (Hook. f.) Hook. f. | 0920006138 | ||
| Chenopodium aristatum | Clement | A3 | 43--1--ari | L. | 0920005548 | ||
| Chenopodium atriplicinum | Starry Goosefoot | Clement | A3 | 43--1--atr | (F. Muell.) F. Muell. | 0920006139 | |
| Chenopodium auricomiforme | Clement | A3 | 43--1--aur | Murr & Thell. | 0920006140 | ||
| Chenopodium berlandieri | Pitseed Goosefoot | Stace | A2 | 43--1--ber | Ca | Moq. | 0920000483 |
| Chenopodium bonus-henricus | Good-King-Henry | Page 19 | A1 | 43--1--4 | Ar | L. | 0920000484 |
| Chenopodium borbasioides | Clement | A3 | 43--1--bor | A. Ludw. ex Asch. & Graebn. | 0920006141 | ||
| Chenopodium botrys | Sticky Goosefoot | Clement | A3 | 43--1--bot | L. | 0920004073 | |
| Chenopodium bushianum | Soyabean Goosefoot | Stace | A2 | 43--1--bus | Ca | Aellen | 0920007992 |
| Chenopodium capitatum | Strawberry-blite | Yes | A1 | 43--1--3 | Ne | (L.) Ambrosi | 0920000486 |
| Chenopodium carinatum | Keeled Goosefoot | Stace | A2 | 43--1--car | Ca | R. Br. | 0920007993 |
| Chenopodium carinatum x cristatum = C. x bontei | Stace | A2 | 43--1--car x cri | Ne | Aellen | 0920007846 | |
| Chenopodium chenopodioides | Saltmarsh Goosefoot | Yes | A1 | 43--1--7 | N | (L.) Aellen | 0920000485 |
| Chenopodium cristatum | Crested Goosefoot | Stace | A2 | 43--1--cri | Ca | (F. Muell.) F. Muell. | 0920007994 |
| Chenopodium desiccatum | Slimleaf Goosefoot | Stace | A2 | 43--1--des | Ca | A. Nelson | 0920000494 |
| Chenopodium detestans | Fish-guts | Clement | A3 | 43--1--det | Kirk | 0920004205 | |
| Chenopodium ficifolium | Fig-leaved Goosefoot | Page 21 | A1 | 43--1--13 | Ar | Sm. | 0920000487 |
| Chenopodium foliosum | Strawberry Goosefoot | Clement | A3 | 43--1--fol | (Moench) Asch. | 0920005651 | |
| Chenopodium giganteum | Tree Spinach | Stace | A2 | 43--1--gig | Ca | D. Don | 0920007995 |
| Chenopodium glaucum | Oak-leaved Goosefoot | Yes | A1 | 43--1--5 | Ar | L. | 0920000488 |
| Chenopodium graveolens | Clement | A3 | 43--1--gra | Lag. & Rodr. | 0920006142 | ||
| Chenopodium hircinum | Foetid Goosefoot | Stace | A2 | 43--1--hir | Ca | Schrad. | 0920000489 |
| Chenopodium hybridum | Maple-leaved Goosefoot | Yes | A1 | 43--1--10 | Ar | L. | 0920000490 |
| Chenopodium macrospermum | Clement | A3 | 43--1--mac | Hook. f. | 0920006143 | ||
| Chenopodium missouriense | Soya-bean Goosefoot | Clement | A3 | 43--1--mis | Aellen | 0920006144 | |
| Chenopodium mucronatum | Clement | A3 | 43--1--muc | Thunb. | 0920006145 | ||
| Chenopodium multifidum | Scented Goosefoot | Stace | A2 | 43--1--mul | Ca | L. | 0920007996 |
| Chenopodium murale | Nettle-leaved Goosefoot | Yes | A1 | 43--1--12 | Ar | L. | 0920000491 |
| Chenopodium nitrariaceum | Nitre Goosefoot | Stace | A2 | 43--1--nit | Ca | (F. Muell.) F. Muell. ex Benth. | 0920007997 |
| Chenopodium opulifolium | Grey Goosefoot | Yes | A1 | 43--1--14 | Ne | Schrad. ex W.D.J. Koch & Ziz | 0920000492 |
| Chenopodium pallidicaule | Clement | A3 | 43--1--pal | Aellen | 0920006146 | ||
| Chenopodium phillipsianum | Clement | A3 | 43--1--phi | Aellen | 0920006147 | ||
| Chenopodium polyspermum | Many-seeded Goosefoot | Page 21 | A1 | 43--1--8 | Ar | L. | 0920000493 |
| Chenopodium probstii | Probst's Goosefoot | Stace | A2 | 43--1--prb | Ca | Aellen | 0920004426 |
| Chenopodium procerum | Clement | A3 | 43--1--pro | Hochst. ex Moq. | 0920006148 | ||
| Chenopodium pumilio | Clammy Goosefoot | Yes | A1 | 43--1--2 | Ne | R. Br. | 0920007223 |
| Chenopodium purpurascens | Purple Goosefoot | Clement | A3 | 43--1--pur | Jacq. | 0920006149 | |
| Chenopodium quinoa | Quinoa | Clement | A3 | 43--1--qui | Willd. | 0920007999 | |
| Chenopodium rostratum | Clement | A3 | 43--1--ros | Aellen ex Blom | 0920006150 | ||
| Chenopodium rubrum | Red Goosefoot | Page 21 | A1 | 43--1--6 | N | L. | 0920000496 |
| Chenopodium rugosum | Clement | A3 | 43--1--rug | Aellen | 0920006151 | ||
| Chenopodium schraderianum | Clement | A3 | 43--1--sch | Schult. | 0920004095 | ||
| Chenopodium solitarium | Clement | A3 | 43--1--sol | Murr | 0920006152 | ||
| Chenopodium strictum | Striped Goosefoot | Stace | A2 | 43--1--str | Ca | Roth | 0920008000 |
| Chenopodium subpalmatum | Clement | A3 | 43--1--sub | Murr ex Druce | 0920006153 | ||
| Chenopodium suecicum | Swedish Goosefoot | Yes S1 | A1 | 43--1--sue | Ne | Murr | 0920000497 |
| Chenopodium urbicum | Upright Goosefoot | Yes | A1 | 43--1--11 | Ar | L. | 0920000498 |
| Chenopodium vulvaria | Stinking Goosefoot | Yes | A1 | 43--1--9 | Ar | L. | 0920000500 |
| Chevreulia sarmentosa | Clement | A3 | 135--CHE--sar | (Pers.) Blake | 0920006154 | ||
| Chiastophyllum oppositifolium | Lamb's-tail | Clement | A3 | 73--CHI--opp | (Ledeb. ex Nordm.) A. Berger | 0920004143 | |
| Chimonobambusa marmorea | Clement | A3 | 153--6--mar | (Mitford) Makino | 0920006155 | ||
| Chimonobambusa quadrangularis | Square-stemmed Bamboo | Yes | A1 | 153--6--1 | Ne | (Franceschi) Makino | 0920004301 |
| Chionodoxa forbesii | Glory-of-the-snow | Yes | A1 | 158--22--1 | Ne | Baker | 0920007224 |
| Chionodoxa luciliae | Boissier's Glory-of-the-snow | Yes S1 | A1 | 158--22--luc | Ne | Boiss. | 0920003338 |
| Chionodoxa nana | Clement | A3 | 158--22--nan | (Schult. & Schult. f.) Boiss. & Heldr. | 0920006156 | ||
| Chionodoxa sardensis | Lesser Glory-of-the-snow | Yes | A1 | 158--22--2 | Ne | Whittall ex Barr | 0920007225 |
| Chloris divaricata | Australian Rhodes-grass | Stace | A2 | 153--CHL--div | Ca | R. Br. | 0920003243 |
| Chloris pectinata | Clement | A3 | 153--CHL--pec | Benth. | 0920006157 | ||
| Chloris pumilio | Clement | A3 | 153--CHL--pum | R. Br. | 0920006158 | ||
| Chloris pycnothrix | Clement | A3 | 153--CHL--pyc | Trin. | 0920006159 | ||
| Chloris radiata | Clement | A3 | 153--CHL--rad | (L.) Sw. | 0920006160 | ||
| Chloris truncata | Windmill-grass | Stace | A2 | 153--CHL--tru | Ca | R. Br. | 0920003242 |
| Chloris ventricosa | Clement | A3 | 153--CHL--ven | R. Br. | 0920006161 | ||
| Chloris virgata | Feathery Rhodes-grass | Stace | A2 | 153--CHL--vir | Ca | Sw. | 0920003244 |
| Chlorophytum comosum | Spider-plant | Clement | A3 | 158--CHL--com | (Thunb.) Jacques | 0920006162 | |
| Choisya ternata | Mexican Orange | Yes S1 | A1 | 101A--CHO--ter | Ne | Kunth | 0920008001 |
| Chondrilla juncea | Skeletonweed | Clement | A3 | 135--CHO--jun | L. | 0920006163 | |
| Chondrosum trifidum | Red Grama | Clement | A3 | 153--CHO--tri | (Thurb.) Clayton | 0920006164 | |
| Chorispora syriaca | Clement | A3 | 62--CHO--syr | Boiss. | 0920006165 | ||
| Chorispora tenella | Clement | A3 | 62--CHO--ten | (Pall.) DC. | 0920004482 | ||
| Chrozophora tinctoria | Turn-sole | Clement | A3 | 91--CHR--tin | (L.) A. Juss. | 0920004206 | |
| Chrysocoma coma-aurea | Shrub Goldilocks | Yes | A1 | 135--42--1 | Ne | L. | 0920007226 |
| Chrysocoma tenuifolia | Fine-leaved Goldilocks | Stace | A2 | 135--42--ten | Ca | P.J. Bergius | 0920008003 |
| Chrysogonum virginianum | Golden-knee | Clement | A3 | 135--CHR--vir | L. | 0920006166 | |
| Chrysosplenium alternifolium | Alternate-leaved Golden-saxifrage | Page 21 | A1 | 74--9--2 | N | L. | 0920000505 |
| Chrysosplenium oppositifolium | Opposite-leaved Golden-saxifrage | Page 21 | A1 | 74--9--1 | N | L. | 0920000506 |
| Cicendia filiformis | Yellow Centaury | Yes | A1 | 108--1--1 | N | (L.) Delarbre | 0920000507 |
| Cicer arietinum | Chick Pea | Stace | A2 | 77--CIC--ari | Ca | L. | 0920008004 |
| Cicerbita alpina | Alpine Blue-sow-thistle | Yes | A1 | 135--23--1 | N | (L.) Wallr. | 0920000508 |
| Cicerbita bourgaei | Pontic Blue-sow-thistle | Yes | A1 | 135--23--4 | Ne | (Boiss.) Beauverd | 0920002531 |
| Cicerbita macrophylla | Common Blue-sow-thistle | Yes | A1 | 135--23--2 | Ne | (Willd.) Wallr. | 0920002381 |
| Cicerbita macrophylla subsp. uralensis | Yes | A1 | 135--23--2--a | (Rouy) P.D. Sell | 0920002381.2 | ||
| Cicerbita plumieri | Hairless Blue-sow-thistle | Yes | A1 | 135--23--3 | Ne | (L.) Kirschl. | 0920004519 |
| Cichorium endivia | Endive | Clement | A3 | 135--12--end | L. | 0920005595 | |
| Cichorium intybus | Chicory | Page 21 | A1 | 135--12--1 | Ar | L. | 0920000509 |
| Ciclospermum leptophyllum | Slender Celery | Clement | A3 | 107--CIC--lep | (Pers.) Britton & E.H. Wilson | 0920006167 | |
| Cicuta virosa | Cowbane | Yes | A1 | 107--31--1 | N | L. | 0920000510 |
| Cineraria aspera | Clement | A3 | 135--CIN--asp | Thunb. | 0920006168 | ||
| Cineraria burkei | Clement | A3 | 135--CIN--bur | Burtt Davy | 0920006169 | ||
| Cineraria geifolia | Clement | A3 | 135--CIN--gei | L. | 0920006170 | ||
| Cineraria lobata | Clement | A3 | 135--CIN--lob | L'H‚r. | 0920006171 | ||
| Cineraria lyrata | Clement | A3 | 135--CIN--lyr | DC. | 0920006172 | ||
| Circaea alpina | Alpine Enchanter's-nightshade | Yes | A1 | 84--6--2 | N | L. | 0920000511 |
| Circaea lutetiana | Enchanter's-nightshade | Page 21 | A1 | 84--6--1 | N | L. | 0920000513 |
| Circaea lutetiana x alpina = C. x intermedia | Upland Enchanter's-nightshade | Yes | A1 | 84--6--1 x 2 | N | Ehrh. | 0920000512 |
| Cirsium acaule | Dwarf Thistle | Page 21 | A1 | 135--6--8 | N | (L.) Scop. | 0920000514 |
| Cirsium acaule x arvense = C. x boulayi | Yes | A1 | 135--6--8 x 10 | E.G. Camus | 0920002833 | ||
| Cirsium acaule x palustre = C. x kirschlegeri | Yes | A1 | 135--6--8 x 9 | Sch. Bip. | 0920002829 | ||
| Cirsium arvense | Creeping Thistle | Page 21 | A1 | 135--6--10 | N | (L.) Scop. | 0920000515 |
| Cirsium creticum | Clement | A3 | 135--6--cre | (Lam.) d'Urv. | 0920006173 | ||
| Cirsium dissectum | Meadow Thistle | Page 21 | A1 | 135--6--3 | N | (L.) Hill | 0920000516 |
| Cirsium dissectum x acaule = C. x woodwardii | Yes | A1 | 135--6--3 x 8 | (H.C. Watson) Nyman | 0920002834 | ||
| Cirsium dissectum x palustre = C. x forsteri | Yes | A1 | 135--6--3 x 9 | N | (Sm.) Loudon | 0920002831 | |
| Cirsium edule | Indian Thistle | Clement | A3 | 135--6--edu | Nutt. | 0920006174 | |
| Cirsium eriophorum | Woolly Thistle | Page 21 | A1 | 135--6--1 | N | (L.) Scop. | 0920000517 |
| Cirsium eriophorum x vulgare = C. x grandiflorum | Yes | A1 | 135--6--1 x 2 | Kitt. | 0920002826 | ||
| Cirsium erisithales | Yellow Thistle | Yes | A1 | 135--6--5 | Ne | (Jacq.) Scop. | 0920007227 |
| Cirsium heterophyllum | Melancholy Thistle | Page 21 | A1 | 135--6--6 | N | (L.) Hill | 0920000518 |
| Cirsium heterophyllum x palustre = C. x wankelii | Yes | A1 | 135--6--6 x 9 | Reichardt | 0920002830 | ||
| Cirsium italicum | Clement | A3 | 135--6--ita | (Savi) DC. | 0920006175 | ||
| Cirsium monspessulanum | Clement | A3 | 135--6--mon | (L.) Hill | 0920006176 | ||
| Cirsium oleraceum | Cabbage Thistle | Yes | A1 | 135--6--7 | Ne | (L.) Scop. | 0920000519 |
| Cirsium palustre | Marsh Thistle | Page 21 | A1 | 135--6--9 | N | (L.) Scop. | 0920000520 |
| Cirsium palustre x arvense = C. x celakovskianum | Yes | A1 | 135--6--9 x 10 | Knaf | 0920002828 | ||
| Cirsium rivulare | Brook Thistle | Clement | A3 | 135--6--riv | (Jacq.) All. | 0920006177 | |
| Cirsium tuberosum | Tuberous Thistle | Yes | A1 | 135--6--4 | N | (L.) All. | 0920000521 |
| Cirsium tuberosum x acaule = C. x medium | Yes | A1 | 135--6--4 x 8 | All. | 0920002835 | ||
| Cirsium tuberosum x palustre = C. x semidecurrens | Yes | A1 | 135--6--4 x 9 | Richt. | 0920002832 | ||
| Cirsium vulgare | Spear Thistle | Page 21 | A1 | 135--6--2 | N | (Savi) Ten. | 0920000522 |
| Cirsium vulgare x acaule = C. x sabaudum | Yes | A1 | 135--6--2 x 8 | M. Loehr | 0920002827 | ||
| Cirsium vulgare x palustre = C. x subspinuligerum | Yes | A1 | 135--6--2 x 9 | Peterm. | 0920007228 | ||
| Cistus albidus | Grey-leaved Cistus | Clement | A3 | 56--CIS--alb | L. | 0920006178 | |
| Cistus albidus x crispus = C. x pulverulentus | Clement | A3 | 56--CIS--alb x cri | Pourr. | 0920006182 | ||
| Cistus incanus | Hoary Rock-rose | Clement | A3 | 56--CIS--inc | L. | 0920008005 | |
| Cistus ladanifer | Gum Rock-rose | Clement | A3 | 56--CIS--lad | L. | 0920006179 | |
| Cistus laurifolius | Laurel-leaved Cistus | Clement | A3 | 56--CIS--lau | L. | 0920008006 | |
| Cistus populifolius x psilosepalus = C. x laxus | Clement | A3 | 56--CIS--pop x psi | W.T. Aiton | 0920006181 | ||
| Cistus populifolius x salviifolius = C. x corbariensis | CorbiŠres Rock-rose | Clement | A3 | 56--CIS--pop x sal | Pourr. | 0920006180 | |
| Cistus salviifolius | Sage-leaved Rock-rose | Clement | A3 | 56--CIS--sal | L. | 0920004207 | |
| Citrullus colocynthis | Bitter Cucumber | Clement | A3 | 60--CIT--col | (L.) Schrad. | 0920006183 | |
| Citrullus lanatus | Water Melon | Stace | A2 | 60--CIT--lan | Ca | (Thunb.) Matsum. & Nakai | 0920008007 |
| Citrus auriantium | Orange | Clement | A3 | 101A--CIT--aur | L. | 0920006184 | |
| Citrus limon | Lemon | Clement | A3 | 101A--CIT--lim | (L.) Burm. f. | 0920006185 | |
| Citrus paradisi | Grapefruit | Clement | A3 | 101A--CIT--par | Macfad. | 0920006186 | |
| Citrus reticulata | Mandarin Orange | Clement | A3 | 101A--CIT--ret | Blanco | 0920006187 | |
| Cladanthus arabicus | Clement | A3 | 135--CLA--ara | (L.) Cass. | 0920004208 | ||
| Cladium mariscus | Great Fen-sedge | Yes | A1 | 152--14--1 | N | (L.) Pohl | 0920000523 |
| Clarkia amoena | Godetia | Stace | A2 | 84--CLA--amo | Ca | (Lehm.) A. Nelson & J.F. Macbr. | 0920008008 |
| Clarkia bottae | Clement | A3 | 84--CLA--bot | (Spach) F.H. Lewis & M.R. Lewis | 0920006189 | ||
| Clarkia concinna | Red-ribbons | Clement | A3 | 84--CLA--con | (Fisch. & C.A. Mey.) Greene | 0920004101 | |
| Clarkia pulchella | Clement | A3 | 84--CLA--pul | Pursh | 0920006190 | ||
| Clarkia purpurea | Clement | A3 | 84--CLA--pur | (Curtis) A. Nelson & J. Macbr. | 0920006191 | ||
| Clarkia quadrivulnera | Clement | A3 | 84--CLA--qua | (Douglas) A. Nelson & J. Macbr. | 0920004144 | ||
| Clarkia unguiculata | Clarkia | Stace | A2 | 84--CLA--ung | Ca | Lindl. | 0920008009 |
| Claytonia perfoliata | Springbeauty | Page 21 | A1 | 45--2--1 | Ne | Donn ex Willd. | 0920000525 |
| Claytonia sibirica | Pink Purslane | Page 21 | A1 | 45--2--2 | Ne | L. | 0920000524 |
| Claytonia virginica | Virginia Springbeauty | Clement | A3 | 45--2--vir | L. | 0920000526 | |
| Clematis armandii | Clement | A3 | 28--12--arm | Franch. | 0920006192 | ||
| Clematis cirrhosa | Early Virgin's-bower | Clement | A3 | 28--12--cir | L. | 0920008010 | |
| Clematis flammula | Virgin's-bower | Yes | A1 | 28--12--2 | Ne | L. | 0920002256 |
| Clematis montana | Himalayan Clematis | Yes | A1 | 28--12--4 | Ne | Buch.-Ham. ex DC. | 0920000527 |
| Clematis tangutica | Orange-peel Clematis | Yes | A1 | 28--12--3 | Ne | (Maxim.) Korsh. | 0920007229 |
| Clematis vitalba | Traveller's-joy | Page 21 | A1 | 28--12--1 | N | L. | 0920000528 |
| Clematis viticella | Purple Clematis | Yes | A1 | 28--12--5 | Ne | L. | 0920000529 |
| Cleome gynandra | Clement | A3 | 61A--CLE--gyn | L. | 0920006193 | ||
| Cleome serrulata | Rocky Mountain Beeplant | Clement | A3 | 61A--CLE--ser | Pursh | 0920006194 | |
| Cleome sesquiorgyalis | Spiderflower | Clement | A3 | 61A--CLE--ses | Naudin ex C. Huber | 0920004118 | |
| Cleretum bellidiforme | Livingstone-daisy | Clement | A3 | 42--CLE--bel | (Burm. f.) G.D. Rowley | 0920005549 | |
| Clerodendrum trichotomum | Clement | A3 | 117--CLE--tri | Thunb. | 0920006195 | ||
| Clethra alnifolia | Sweet Pepperbush | Clement | A3 | 63A--CLE--aln | L. | 0920006196 | |
| Clethra arborea | Lily-of-the-valley-tree | Clement | A3 | 63A--CLE--arb | Aiton | 0920008012 | |
| Clinopodium acinos | Basil Thyme | Page 21 | A1 | 118--18--5 | N | (L.) Kuntze | 0920000012 |
| Clinopodium ascendens | Common Calamint | Page 21 | A1 | 118--18--2 | N | (Jord.) Samp. | 0920000296 |
| Clinopodium calamintha | Lesser Calamint | Yes | A1 | 118--18--3 | N | (L.) Stace | 0920000298 |
| Clinopodium grandiflorum | Greater Calamint | Clement | A3 | 118--18--gra | (L.) Stace | 0920008013 | |
| Clinopodium menthifolium | Wood Calamint | Yes | A1 | 118--18--1 | N | (Host) Stace | 0920000297 |
| Clinopodium rotundifolium | Round-leaved Calamint | Clement | A3 | 118--18--rot | Pers. | 0920005602 | |
| Clinopodium vulgare | Wild Basil | Page 23 | A1 | 118--18--4 | N | L. | 0920000530 |
| Clypeola jonthlaspi | Disk Cress | Clement | A3 | 62--CLY--jon | L. | 0920006197 | |
| Cnicus benedictus | Blessed Thistle | Clement | A3 | 135--CNI--ben | L. | 0920008014 | |
| Cochlearia anglica | English Scurvygrass | Page 23 | A1 | 62--23--1 | N | L. | 0920000532 |
| Cochlearia anglica x officinalis = C. x hollandica | Yes | A1 | 62--23--1 x 3 | Henrard | 0920002624 | ||
| Cochlearia danica | Danish Scurvygrass | Page 23 | A1 | 62--23--5 | N | L. | 0920000533 |
| Cochlearia megalosperma | Tall Scurvygrass | Yes S1 | A1 | 62--23--meg | Ne | (Maire) Vogt | 0920003343 |
| Cochlearia micacea | Mountain Scurvygrass | Yes | A1 | 62--23--4 | N | E.S. Marshall | 0920000534 |
| Cochlearia officinalis | Common Scurvygrass | Page 23 | A1 | 62--23--3 | N | L. | 0920000535 |
| Cochlearia officinalis agg. | Agregate | AK | 62--23--- | ||||
| Cochlearia officinalis subsp. officinalis | Yes S1 | A1 | 62--23--3--a | 0920003345 | |||
| Cochlearia officinalis subsp. scotica | Scottish Scurvygrass | Yes S1 | A1 | 62--23--3--b | N | (Druce) P.S. Wyse Jacks. | 0920000536 |
| Cochlearia officinalis x danica | Yes | A1 | 62--23--3 x 5 | 0920002623 | |||
| Cochlearia pyrenaica | Pyrenean Scurvygrass | Yes | A1 | 62--23--2 | N | DC. | 0920005422 |
| Cochlearia pyrenaica subsp. alpina | Yes S1 | A1 | 62--23--2--b | (Bab.) Dalby | 0920005422.1 | ||
| Cochlearia pyrenaica subsp. pyrenaica | Yes S1 | A1 | 62--23--2--a | 0920005422.2 | |||
| Cochlearia pyrenaica x officinalis | Yes | A1 | 62--23--2 x 3 | 0920007230 | |||
| Coeloglossum viride | Frog Orchid | Page 23 | A1 | 162--17--1 | N | (L.) Hartm. | 0920000537 |
| Coeloglossum viride x Dactylorhiza fuchsii = X Dactyloglossum mixtum | Yes | A1 | 162--17 x 18--1 x 1 | (Asch. & Graebn.) Rauschert | 0920002847 | ||
| Coeloglossum viride x Dactylorhiza maculata = X Dactyloglossum conigerum | Yes S1 | A1 | 162--17 x 18--1 x 2 | (Norman) Rauschert | 0920002848 | ||
| Coeloglossum viride x Dactylorhiza purpurella = X Dactyloglossum viridella | Yes | A1 | 162--17 x 18--1 x 5 | (Hesl.-Harr. f.) So¢ | 0920002849 | ||
| Coincya hispida | Wallflower Cabbage | Clement | A3 | 62--37--his | (Cav.) Greuter & Burdet | 0920006198 | |
| Coincya longirostra | Clement | A3 | 62--37--lon | (Boiss.) Greuter & Burdet | 0920006199 | ||
| Coincya monensis | Yes | A1 | 62--37--1 | (L.) Greuter & Burdet | 0920005396 | ||
| Coincya monensis subsp. cheiranthos | Wallflower Cabbage | Yes S1 | A1 | 62--37--1--b | Ne | (Vill.) Aedo, Leadlay & Mu¤oz Garm. | 0920001688 |
| Coincya monensis subsp. monensis | Isle-of-Man Cabbage | Yes | A1 | 62--37--1--a | N | 0920001689 | |
| Coincya wrightii | Lundy Cabbage | Yes | A1 | 62--37--2 | N | (O.E. Schulz) Stace | 0920001690 |
| Coix lacryma-jobi | Job's-tears | Clement | A3 | 153--COI--lac | L. | 0920006200 | |
| Colchicum agrippinum | Clement | A3 | 158--7--agr | hort. ex Baker | 0920006201 | ||
| Colchicum autumnale | Meadow Saffron | Page 23 | A1 | 158--7--1 | N | L. | 0920000538 |
| Colchicum byzantinum | Clement | A3 | 158--7--byz | Ker Gawl. | 0920006202 | ||
| Colchicum variegatum | Clement | A3 | 158--7--var | L. | 0920006203 | ||
| Coleostephus myconis | Clement | A3 | 135--COL--myc | (L.) Rchb. f. | 0920006204 | ||
| Coleus blumei | Painted-nettle | Clement | A3 | 118--COL--blu | Benth. | 0920006205 | |
| Collinsia heterophylla | Chinese-houses | Clement | A3 | 124--COL--het | G. Buist ex Graham | 0920006206 | |
| Collomia biflora | Clement | A3 | 114--COL--bif | (Ruiz & Pav.) Brand | 0920006207 | ||
| Collomia grandiflora | Clement | A3 | 114--COL--gra | Douglas ex Hook. | 0920005591 | ||
| Collomia linearis | Clement | A3 | 114--COL--lin | Nutt. | 0920006208 | ||
| Colocasia esculenta | Taro | Clement | A3 | 147--COL--esc | (L.) Schott | 0920006209 | |
| Colutea arborescens | Bladder-senna | Yes | A1 | 77--3--1 | Ne | L. | 0920000539 |
| Colutea arborescens x orientalis = C. x media | Orange Bladder-senna | Yes | A1 | 77--3--1 x ori | Ne | Willd. | 0920007231 |
| Commelina coelestis | Blue Spiderwort | Clement | A3 | 149--COM--coe | Willd. | 0920006210 | |
| Commelina communis | Clement | A3 | 149--COM--com | L. | 0920006211 | ||
| Commelina diffusa | Creeping Spiderwort | Clement | A3 | 149--COM--dif | Burm. f. | 0920006212 | |
| Commelina elliptica | Peruvian Spiderwort | Clement | A3 | 149--COM--ell | Kunth | 0920006213 | |
| Commelina virginica | Clement | A3 | 149--COM--vir | L. | 0920006214 | ||
| Conium maculatum | Hemlock | Page 23 | A1 | 107--25--1 | Ar | L. | 0920000540 |
| Conopodium majus | Pignut | Page 23 | A1 | 107--12--1 | N | (Gouan) Loret | 0920000541 |
| Conringia austriaca | Stace | A3 | 62--CON--aus | (Jacq.) Sweet | 0920004483 | ||
| Conringia orientalis | Hare's-ear Mustard | Stace | A2 | 62--CON--ori | Ca | (L.) Dumort. | 0920000542 |
| Consolida ajacis | Larkspur | Yes | A1 | 28--7--1 | Ne | (L.) Schur | 0920000622 |
| Consolida orientalis | Eastern Larkspur | Clement | A3 | 28--7--ori | (J. Gay ex Des Moul.) Schr”dinger | 0920000624 | |
| Consolida pubescens | Clement | A3 | 28--7--pub | (DC.) So¢ | 0920006215 | ||
| Consolida regalis | Forking Larkspur | Clement | A3 | 28--7--reg | Gray | 0920000623 | |
| Convallaria majalis | Lily-of-the-valley | Page 23 | A1 | 158--13--1 | N | L. | 0920000543 |
| Convolvulus althaeoides | Mallow-leaved Bindweed | Clement | A3 | 111--2--alt | L. | 0920006216 | |
| Convolvulus arvensis | Field Bindweed | Page 23 | A1 | 111--2--1 | N | L. | 0920000544 |
| Convolvulus betonicifolius | Clement | A3 | 111--2--bet | Mill. | 0920006217 | ||
| Convolvulus erubescens | Australian Bindweed | Clement | A3 | 111--2--eru | Sims | 0920006218 | |
| Convolvulus pentapetaloides | Clement | A3 | 111--2--pen | L. | 0920006219 | ||
| Convolvulus sabatius | Ground Blue-convolvulus | Clement | A3 | 111--2--sab | Viv. | 0920004209 | |
| Convolvulus siculus | Small Blue-convolvulus | Clement | A3 | 111--2--sic | L. | 0920006220 | |
| Convolvulus stachydifolius | Clement | A3 | 111--2--sta | Choisy | 0920006221 | ||
| Convolvulus tricolor | Tricolour Convolvulus | Clement | A3 | 111--2--tri | L. | 0920005619 | |
| Conyza blakei | Clement | A3 | 135--44--bla | (Cabrera) Cabrera | 0920006222 | ||
| Conyza bonariensis | Argentine Fleabane | Yes S1 | A1 | 135--44--bon | Ne | (L.) Cronquist | 0920002632 |
| Conyza canadensis | Canadian Fleabane | Page 23 | A1 | 135--44--1 | Ne | (L.) Cronquist | 0920000735 |
| Conyza canadensis x bonariensis | Yes S1 | A1 | 135--44--1 x bon | 0920003346 | |||
| Conyza floribunda | Bilbao Fleabane | Yes S2, S3 | A1 | 135--44--flo | Ne | Kunth | |
| Conyza japonica | Japanese Fleabane | Clement | A3 | 135--44--jap | (Thunb.) Less. | 0920006223 | |
| Conyza sumatrensis | Guernsey Fleabane | Yes | A1 | 135--44--2 | Ne | (Retz.) E. Walker | 0920002633 |
| Coprosma repens | Tree Bedstraw | Yes | A1 | 130--1--1 | Ne | A. Rich. | 0920004391 |
| Corallorhiza trifida | Coralroot Orchid | Yes | A1 | 162--11--1 | N | Chƒtel. | 0920000545 |
| Corchorus olitorius | Tossa Jute | Clement | A3 | 52--COR--oli | L. | 0920006224 | |
| Cordyline australis | Cabbage-palm | Yes | A1 | 160--3--1 | Ne | (G. Forst.) Endl. | 0920007232 |
| Coreopsis grandiflora | Large-flowered Tickseed | Yes | A1 | 135--82--1 | Ne | Hogg ex Sweet | 0920007233 |
| Coreopsis nuecensis | Clement | A3 | 135--82--nue | A. Heller | 0920006225 | ||
| Coreopsis tinctoria | Garden Tickseed | Clement | A3 | 135--82--tin | Nutt. | 0920008016 | |
| Coreopsis verticillata | Whorled Tickseed | Clement | A3 | 135--82--ver | L. | 0920008017 | |
| Coriandrum sativum | Coriander | Yes | A1 | 107--9--1 | Ne | L. | 0920000546 |
| Coriandrum tordylium | Clement | A3 | 107--9--tor | (Fenzl) Bornm. | 0920006226 | ||
| Corispermum hyssopifolium | Hyssop-leaved Bugseed | Clement | A3 | 43--COR--hys | L. | 0920006227 | |
| Corispermum leptopterum | Bugseed | Yes S1 | A1 | 43--COR--lep | Ne | (Asch.) Iljin | 0920003347 |
| Cornucopiae cucullatum | Clement | A3 | 153--COR--cuc | L. | 0920006228 | ||
| Cornus alba | White Dogwood | Yes | A1 | 85--1--3 | Ne | L. | 0920000547 |
| Cornus alternifolia | Pagoda Dogwood | Clement | A3 | 85--1--alt | L. | 0920006229 | |
| Cornus canadensis | Creeping Dogwood | Clement | A3 | 85--1--can | L. | 0920006230 | |
| Cornus capitata | Bentham's Dogwood | Clement | A3 | 85--1--cap | Wall. | 0920004182 | |
| Cornus florida | Flowering Dogwood | Clement | A3 | 85--1--flo | L. | 0920006231 | |
| Cornus kousa | Clement | A3 | 85--1--kou | Hance | 0920006232 | ||
| Cornus mas | Cornelian-cherry | Yes | A1 | 85--1--4 | Ne | L. | 0920005423 |
| Cornus sanguinea | Dogwood | Page 23 | A1 | 85--1--1 | N | L. | 0920000548 |
| Cornus sericea | Red-osier Dogwood | Yes | A1 | 85--1--2 | Ne | L. | 0920000549 |
| Cornus suecica | Dwarf Cornel | Page 23 | A1 | 85--1--5 | N | L. | 0920000478 |
| Coronilla coronata | Scorpion-vetch | Clement | A3 | 77--11--cor | L. | 0920006233 | |
| Coronilla scorpioides | Annual Scorpion-vetch | Yes | A1 | 77--11--2 | Ca | (L.) W.D.J. Koch | 0920007234 |
| Coronilla valentina | Shrubby Scorpion-vetch | Yes | A1 | 77--11--1 | Ne | L. | 0920007119 |
| Coronilla valentina subsp. glauca | Yes | A1 | 77--11--1--a | (L.) Battand. | 0920007119 | ||
| Coronopus didymus | Lesser Swine-cress | Page 23 | A1 | 62--31--2 | Ne | (L.) Sm. | 0920000551 |
| Coronopus squamatus | Swine-cress | Page 23 | A1 | 62--31--1 | Ar | (Forssk.) Asch. | 0920000552 |
| Correa backhouseana | Tasmanian-fuchsia | Yes S1 | A1 | 101A--COR--bac | Ne | Hook. | 0920003340 |
| Corrigiola litoralis | Strapwort | Yes | A1 | 46--12--1 | N | L. | 0920000553 |
| Corrigiola telephiifolia | Clement | A3 | 46--12--tel | Pourr. | 0920008018 | ||
| Cortaderia richardii | Early Pampas-grass | Yes S1 | A1 | 153--62--ric | Ne | (Endl.) Zotov | 0920003351 |
| Cortaderia selloana | Pampas-grass | Yes | A1 | 153--62--1 | Ne | (Schult. & Schult. f.) Asch. & Graebn. | 0920004392 |
| Corydalis capnoides | Beaked Corydalis | Clement | A3 | 31--2--cap | (L.) Pers. | 0920006234 | |
| Corydalis cava | Hollowroot | Yes | A1 | 31--2--2 | Ne | (L.) Schweigg. & K”rte | 0920004403 |
| Corydalis cheilanthifolia | Fern-leaved Corydalis | Yes | A1 | 31--2--3 | Ne | Hemsl. | 0920007235 |
| Corydalis ophiocarpa | Clement | A3 | 31--2--oph | Hook. f. & Thomson | 0920006235 | ||
| Corydalis sempervirens | Harlequin Corydalis | Clement | A3 | 31--2--sem | (L.) Pers. | 0920006236 | |
| Corydalis solida | Bird-in-a-bush | Yes | A1 | 31--2--1 | Ne | (L.) Clairv. | 0920000554 |
| Corylus avellana | Hazel | Page 23 | A1 | 40--4--1 | N | L. | 0920000557 |
| Corylus avellana x maxima | Yes | A1 | 40--4--1 x 2 | Ne | 0920007236 | ||
| Corylus colurna | Turkish Hazel | Stace | A2 | 40--4--col | Ne | L. | 0920003352 |
| Corylus maxima | Filbert | Yes | A1 | 40--4--2 | Ne | Mill. | 0920005424 |
| Corynephorus canescens | Grey Hair-grass | Yes | A1 | 153--34--1 | N | (L.) P. Beauv. | 0920000558 |
| Cosmos bipinnatus | Mexican Aster | Yes | A1 | 135--83--1 | Ne | Cav. | 0920007237 |
| Cotinus coggygria | Smoke-tree | Clement | A3 | 100--COT--cog | Scop. | 0920008019 | |
| Cotoneaster acuminatus | Clement | A3 | 75--32--acu | Lindl. | 0920006237 | ||
| Cotoneaster adpressus | Creeping Cotoneaster | Yes | A1 | 75--32--24 | Ne | Bois | 0920002925 |
| Cotoneaster affinis | Purpleberry Cotoneaster | Yes | A1 | 75--32--5 | Ne | Lindl. | 0920002926 |
| Cotoneaster amoenus | Beautiful Cotoneaster | Yes | A1 | 75--32--42 | Ne | E.H. Wilson | 0920007238 |
| Cotoneaster apiculatus | Apiculate Cotoneaster | Yes S1 | A1 | 75--32--api | Ne | Rehder & E.H. Wilson | 0920003357 |
| Cotoneaster ascendens | Ascending Cotoneaster | Yes S1 | A1 | 75--32--asc | Ne | Flinck & B. Hylm” | 0920003362 |
| Cotoneaster astrophoros | Starry Cotoneaster | Yes S1 | A1 | 75--32--ast | Ne | J. Fryer & E.C. Nelson | 0920003366 |
| Cotoneaster atropurpureus | Purple-flowered Cotoneaster | Yes | A1 | 75--32--23 | Ne | Flinck & B. Hylm” | 0920007239 |
| Cotoneaster bacillaris | Open-fruited Cotoneaster | Yes | A1 | 75--32--7 | Ne | Wall. ex Lindl. | 0920002927 |
| Cotoneaster boisianus | Bois's Cotoneaster | Yes S1 | A1 | 75--32--boi | Ne | G. Klotz | 0920003367 |
| Cotoneaster bradyi | Brady's Cotoneaster | Yes S3 | A1 | 75--32--bra | Ne | E.C. Nelson J. Fryer | |
| Cotoneaster bullatus | Hollyberry Cotoneaster | Yes | A1 | 75--32--34 | Ne | Bois | 0920002928 |
| Cotoneaster buxifolius | Box-leaved Cotoneaster | Clement | A3 | 75--32--bux | Wall. ex Lindl. | 0920006238 | |
| Cotoneaster calocarpus | Sikang Cotoneaster | Yes S2 | A1 | 75--32--cal | (Rehder & E.H. Wilson) Flinck & B. Hylm” | 0920002930 | |
| Cotoneaster cambricus | Wild Cotoneaster | Yes S1 | A1 | 75--32--31 | Ne | J. Fryer & B. Hylm” | 0920000561 |
| Cotoneaster cashmiriensis | Kashmir Cotoneaster | Yes | A1 | 75--32--19 | Ne | G. Klotz | 0920002932 |
| Cotoneaster cinerascens | Clement | A3 | 75--32--cin | (Rehder) Flinck & B. Hylm” | 0920002931 | ||
| Cotoneaster cochleatus | Yunnan Cotoneaster | Yes S1 | A1 | 75--32--coc | Ne | (Franch.) G. Klotz | 0920003369 |
| Cotoneaster congestus | Congested Cotoneaster | Yes | A1 | 75--32--15 | Ne | Baker | 0920002933 |
| Cotoneaster conspicuus | Tibetan Cotoneaster | Yes | A1 | 75--32--18 | Ne | C. Marquand | 0920002934 |
| Cotoneaster cooperi | Cooper's Cotoneaster | Yes S1 | A1 | 75--32--coo | Ne | C. Marquand | 0920003370 |
| Cotoneaster dammeri | Bearberry Cotoneaster | Yes | A1 | 75--32--11 | Ne | C.K. Schneid. | 0920002936 |
| Cotoneaster dammeri x conspicuus = C. x suecicus | Swedish Cotoneaster | Yes | A1 | 75--32--11 x 18 | Ne | G. Klotz | 0920007249 |
| Cotoneaster dielsianus | Diels' Cotoneaster | Yes | A1 | 75--32--37 | Ne | E. Pritz. ex Diels | 0920002937 |
| Cotoneaster divaricatus | Spreading Cotoneaster | Yes | A1 | 75--32--26 | Ne | Rehder & E.H. Wilson | 0920002938 |
| Cotoneaster ellipticus | Lindley's Cotoneaster | Yes S3 | A1 | 75--32--2 | Ne | (Lindl.) Loudon | 0920007240 |
| Cotoneaster fangianus | Fang's Cotoneaster | Yes S1 | A1 | 75--32--fan | Ne | T.T. Yu | 0920003374 |
| Cotoneaster foveolatus | Clement | A3 | 75--32--fov | Rehder & E.H. Wilson | 0920006239 | ||
| Cotoneaster franchetii | Franchet's Cotoneaster | Yes | A1 | 75--32--39 | Ne | Bois | 0920002939 |
| Cotoneaster frigidus | Tree Cotoneaster | Yes | A1 | 75--32--9 | Ne | Wall. ex Lindl. | 0920000559 |
| Cotoneaster frigidus x salicifolius = C. x watereri | Waterer's Cotoneaster | Yes | A1 | 75--32--9 x 10 | Ne | Exell | 0920002960 |
| Cotoneaster glabratus | Glabrous Cotoneaster | Yes S3 | A1 | 75--32--gla | Ne | Rehder & E.H. Wilson | |
| Cotoneaster glaucophyllus | Glaucous Cotoneaster | Yes S3 | A1 | 75--32--glc | Ne | Franch. | |
| Cotoneaster henryanus | Henry's Cotoneaster | Yes S1 | A1 | 75--32--hen | Ne | (C.K. Schneid.) Rehder & E.H. Wilson | 0920003378 |
| Cotoneaster hissaricus | Circular-leaved Cotoneaster | Yes | A1 | 75--32--3 | Ne | Pojark. | 0920002941 |
| Cotoneaster hjelmqvistii | Hjelmqvist's Cotoneaster | Yes | A1 | 75--32--22 | Ne | Flinck & B. Hylm” | 0920007241 |
| Cotoneaster hodjingensis | Earthquake Cotoneaster | Yes S3 | A1 | 75--32--hod | Ne | G. Klotz | |
| Cotoneaster horizontalis | Wall Cotoneaster | Page 23 | A1 | 75--32--21 | Ne | Decne. | 0920000560 |
| Cotoneaster hsingshangensis | Hsing-Shan Cotoneaster | Yes S2 | A1 | 75--32--hsi | Ne | J. Fryer & B. Hylm” | 0920003797 |
| Cotoneaster hummelii | Hummel's Cotoneaster | Yes S2 | A1 | 75--32--hum | Ne | J. Fryer & B. Hylm” | 0920003798 |
| Cotoneaster hupehensis | Clement | A3 | 75--32--hup | Rehder & E.H. Wilson | 0920006240 | ||
| Cotoneaster hurusawaianus | Hurusawa's Cotoneaster | Yes S3 | A1 | 75--32--hur | Ne | G. Klotz | |
| Cotoneaster hylmoei | Hylm”'s Cotoneaster | Yes S1 | A1 | 75--32--hyl | Ne | Flinck & J. Fryer | 0920003381 |
| Cotoneaster ignescens | Firebird Cotoneaster | Yes S3 | A1 | 75--32--ign | Ne | J. Fryer & B. Hylm” | |
| Cotoneaster ignotus | Black-grape Cotoneaster | Yes | A1 | 75--32--4 | Ne | G. Klotz | 0920007242 |
| Cotoneaster induratus | Hardy Cotoneaster | Yes S2 | A1 | 75--32--ind | J. Fryer & B. Hylm” | ||
| Cotoneaster insculptus | Engraved Cotoneaster | Yes | A1 | 75--32--41 | Ne | Diels | 0920007243 |
| Cotoneaster integrifolius | Entire-leaved Cotoneaster | Yes | A1 | 75--32--16 | Ne | (Roxb.) G. Klotz | 0920000562 |
| Cotoneaster lacteus | Late Cotoneaster | Yes | A1 | 75--32--13 | Ne | W.W. Sm. | 0920002943 |
| Cotoneaster laetevirens | Ampfield Cotoneaster | Yes | A1 | 75--32--30 | Ne | (Rehder & E.H. Wilson) G. Klotz | 0920007244 |
| Cotoneaster lidjiangensis | Lidjiang Cotoneaster | Yes S2 | A1 | 75--32--lid | G. Klotz | ||
| Cotoneaster lucidus | Shiny Cotoneaster | Yes | A1 | 75--32--28 | Ne | Schltdl. | 0920002944 |
| Cotoneaster mairei | Maire's Cotoneaster | Yes S1 | A1 | 75--32--mai | Ne | H. L‚v. | 0920003382 |
| Cotoneaster marginatus | Fringed Cotoneaster | Yes S1 | A1 | 75--32--mar | Ne | (Loudon) Schltdl. | 0920002945 |
| Cotoneaster microphyllus | Small-leaved Cotoneaster | Yes S1 | A1 | 75--32--mic | Ne | Wall. ex Lindl. | 0920003386 |
| Cotoneaster monopyrenus | One-stoned Cotoneaster | Yes S1 | A1 | 75--32--1 | Ne | (W.W. Sm.) Flinck & B. Hylm” | 0920002947 |
| Cotoneaster moupinensis | Moupin Cotoneaster | Yes | A1 | 75--32--36 | Ne | Franch. | 0920002940 |
| Cotoneaster mucronatus | Mucronate Cotoneaster | Yes | A1 | 75--32--32 | Ne | Franch. | 0920002946 |
| Cotoneaster nanshan | Dwarf Cotoneaster | Yes | A1 | 75--32--25 | Ne | M. Vilm. ex Mottet | 0920002948 |
| Cotoneaster newryensis | Clement | A3 | 75--32--new | Lemoine | 0920006241 | ||
| Cotoneaster nitens | Few-flowered Cotoneaster | Yes | A1 | 75--32--27 | Ne | Rehder & E.H. Wilson | 0920002949 |
| Cotoneaster nitidus | Distichous Cotoneaster | Yes | A1 | 75--32--20 | Ne | Jacques | 0920007246 |
| Cotoneaster obscurus | Obscure Cotoneaster | Yes S1 | A1 | 75--32--obs | Ne | Rehder & E.H. Wilson | 0920003388 |
| Cotoneaster obtusus | Dartford Cotoneaster | Yes | A1 | 75--32--6 | Ne | Wall. ex Lindl. | 0920002935 |
| Cotoneaster pannosus | Silverleaf Cotoneaster | Yes | A1 | 75--32--12 | Ne | Franch. | 0920002950 |
| Cotoneaster perpusillus | Slender Cotoneaster | Yes S2 | A1 | 75--32--per | (C.K. Schneid.) Flinck & B. Hylm” | 0920002951 | |
| Cotoneaster prostratus | Procumbent Cotoneaster | Yes S1 | A1 | 75--32--14 | Ne | Baker | 0920002929 |
| Cotoneaster pseudoambiguus | Kangting Cotoneaster | Yes S2 | A1 | 75--32--pse | Ne | J. Fryer & B. Hylm” | 0920003799 |
| Cotoneaster radicans | Rooting Cotoneaster | Yes S2 | A1 | 75--32--rad | G. Klotz | ||
| Cotoneaster rehderi | Bullate Cotoneaster | Yes | A1 | 75--32--35 | Ne | Pojark. | 0920002952 |
| Cotoneaster rotundifolius | Round-leaved Cotoneaster | Yes S1 | A1 | 75--32--rot | Ne | Wall. ex Lindl. | 0920003390 |
| Cotoneaster salicifolius | Willow-leaved Cotoneaster | Yes | A1 | 75--32--10 | Ne | Franch. | 0920002954 |
| Cotoneaster salicifolius x dammeri = C. 'Hybridus Pendulus' | Weeping Cotoneaster | Yes S3 | A1 | 75--32--10 x 11 | hort., nom. nud. | 0920003380 | |
| Cotoneaster sanguineus | Clement | A3 | 75--32--san | T.F. Yu | 0920002955 | ||
| Cotoneaster serotinus | Yuletide Cotoneaster | Yes S2 | A1 | 75--32--ser | Hutch. | 0920006242 | |
| Cotoneaster shannanensis | Shannan Cotoneaster | Yes S3 | A1 | 75--32--sha | Ne | J. Fryer & B. Hylm” | |
| Cotoneaster sherriffii | Sherriff's Cotoneaster | Yes S1 | A1 | 75--32--she | Ne | G. Klotz | 0920003391 |
| Cotoneaster silvestrei | Clement | A3 | 75--32--sil | Pamp. | 0920006243 | ||
| Cotoneaster simonsii | Himalayan Cotoneaster | Page 23 | A1 | 75--32--33 | Ne | Baker | 0920000563 |
| Cotoneaster splendens | Showy Cotoneaster | Yes | A1 | 75--32--38 | Ne | Flinck & B. Hylm” | 0920007247 |
| Cotoneaster sternianus | Stern's Cotoneaster | Yes | A1 | 75--32--40 | Ne | (Turrill) Boom | 0920002957 |
| Cotoneaster tengyuehensis | Tengyueh Cotoneaster | Yes S2 | A1 | 75--32--ten | Ne | J. Fryer & B. Hylm” | 0920003800 |
| Cotoneaster thymifolius | Thyme-leaved Cotoneaster | Yes S3 | A1 | 75--32--17 | Ne | Wall. ex Lindl. | 0920007245 |
| Cotoneaster tomentellus | Short-felted Cotoneaster | Yes S1 | A1 | 75--32--tom | Ne | Pojark. | 0920003397 |
| Cotoneaster transens | Godalming Cotoneaster | Yes | A1 | 75--32--8 | Ne | G. Klotz | 0920007248 |
| Cotoneaster turbinatus | Clement | A3 | 75--32--tur | Craib | 0920006244 | ||
| Cotoneaster veitchii | Many-flowered Cotoneaster | Clement | A3 | 75--32--vei | (Rehder & E.H. Wilson) G. Klotz | 0920006245 | |
| Cotoneaster vestitus | Clement | A3 | 75--32--ves | (W.W. Sm.) Flinck & B. Hylm” | 0920002958 | ||
| Cotoneaster villosulus | Lleyn Cotoneaster | Yes | A1 | 75--32--29 | Ne | (Rehder & E.H. Wilson) Flinck & B. Hylm” | 0920002959 |
| Cotoneaster vilmorinianus | Vilmorin's Cotoneaster | Yes S1 | A1 | 75--32--vil | Ne | G. Klotz | 0920003398 |
| Cotoneaster wardii | Ward's Cotoneaster | Yes S1 | A1 | 75--32--war | Ne | W.W. Sm. | 0920003400 |
| Cotoneaster zabelii | Cherryred Cotoneaster | Yes | A1 | 75--32--43 | Ne | C.K. Schneid. | 0920002961 |
| Cotula anthemoides | Clement | A3 | 135--61--ant | L. | 0920006246 | ||
| Cotula australis | Annual Buttonweed | Yes | A1 | 135--61--2 | Ne | (Sieber ex Spreng.) Hook. f. | 0920007250 |
| Cotula bipinnata | Ferny Buttonweed | Clement | A3 | 135--61--bip | Thunb. | 0920006247 | |
| Cotula coronopifolia | Buttonweed | Yes | A1 | 135--61--1 | Ne | L. | 0920000564 |
| Cotula dioica | Hairless Leptinella | Yes | A1 | 135--61--3 | Ne | (Hook. f.) Hook. f. | 0920007251 |
| Cotula filifolia | Clement | A3 | 135--61--fil | Thunb. | 0920006248 | ||
| Cotula macroglossa | Clement | A3 | 135--61--mac | Bolus ex Schltdl. | 0920006249 | ||
| Cotula pusilla | Clement | A3 | 135--61--pus | Thunb. | 0920006250 | ||
| Cotula sororia | Clement | A3 | 135--61--sor | DC. | 0920006251 | ||
| Cotula squalida | Leptinella | Yes | A1 | 135--61--4 | Ne | (Hook. f.) Hook. f. | 0920007252 |
| Cotula turbinata | Clement | A3 | 135--61--tur | L. | 0920004187 | ||
| Cotula villosa | Clement | A3 | 135--61--vil | DC. | 0920006252 | ||
| Cotula zeyheri | Clement | A3 | 135--61--zey | Fenzl ex Harv. | 0920006253 | ||
| Cousinia tenella | Clement | A3 | 135--COU--ten | (Fisch. & C.A. Mey. ex A. DC.) Fisch. & C.A. Mey. | 0920006254 | ||
| Crambe cordifolia | Greater Sea-kale | Yes | A1 | 62--41--2 | Ne | Steven | 0920004478 |
| Crambe maritima | Sea-kale | Page 23 | A1 | 62--41--1 | N | L. | 0920000565 |
| Crambe orientalis | Oriental Sea-kale | Clement | A3 | 62--41--ori | L. | 0920006255 | |
| Crassocephalum sarcobasis | Clement | A3 | 135--CRA--sar | (DC.) S. Moore | 0920006256 | ||
| Crassula alata | Clement | A3 | 73--1--ala | (Viv.) Berger | 0920006257 | ||
| Crassula alata subsp. pharnaceoides | Clement | A3 | 73--1--ala--a | (Fisch. & C.A. Mey.) Wickens & Bywater | 0920006257.1 | ||
| Crassula aquatica | Pigmyweed | Yes | A1 | 73--1--2 | ?N | (L.) Sch”nland | 0920000566 |
| Crassula campestris | Clement | A3 | 73--1--cam | (Eckl. & Zeyh.) Endl. ex Walp. | 0920006259 | ||
| Crassula colorata | Dense Pigmyweed | Clement | A3 | 73--1--col | (Nees) Ostenf. | 0920006260 | |
| Crassula decumbens | Scilly Pigmyweed | Yes | A1 | 73--1--4 | Ne | Thunb. | 0920007253 |
| Crassula helmsii | New Zealand Pigmyweed | Page 23 | A1 | 73--1--3 | Ne | (Kirk) Cockayne | 0920002423 |
| Crassula intricata | Clement | A3 | 73--1--int | (Nees) Ostenf. | 0920006261 | ||
| Crassula natans | Clement | A3 | 73--1--nat | Thunb. | 0920006262 | ||
| Crassula peduncularis | Purple Pigmyweed | Clement | A3 | 73--1--ped | (Sm.) Meigen | 0920006263 | |
| Crassula pubescens | Jersey Pigmyweed | Clement | A3 | 73--1--pub | Ne | Thunb. | 0920007120 |
| Crassula pubescens subsp. radicans | Clement | A3 | 73--1--pub--a | (Haw.) Toelken | 0920007120 | ||
| Crassula sarmentosa | Jade-tree | Clement | A3 | 73--1--sar | Harv. | 0920006264 | |
| Crassula setulosa | Clement | A3 | 73--1--set | Harv. | 0920006265 | ||
| Crassula sieberiana | Austalian Pigmyweed | Clement | A3 | 73--1--sie | (Schult. & Schult. f.) Druce | 0920006266 | |
| Crassula thunbergiana | Clement | A3 | 73--1--thu | Schult. | 0920006267 | ||
| Crassula tillaea | Mossy Stonecrop | Yes | A1 | 73--1--1 | N | Lest.-Garl. | 0920000567 |
| Crassula vaillantii | Clement | A3 | 73--1--vai | (Willd.) Roth | 0920006268 | ||
| Crataegus coccinea | Pear-fruited Cockspurthorn | Yes S3 | A1 | 75--35--3 | Ne | L. | 0920007258 |
| Crataegus coccinioides | Large-flowered Cockspurthorn | Yes | A1 | 75--35--2 | Ne | Ashe | 0920007254 |
| Crataegus crus-galli | Cockspurthorn | Yes | A1 | 75--35--4 | Ne | L. | 0920007255 |
| Crataegus douglasii | Black Hawthorn | Clement | A3 | 75--35--dou | Lindl. | 0920006269 | |
| Crataegus elliptica | Clement | A3 | 75--35--ell | Aiton | 0920006270 | ||
| Crataegus heterophylla | Various-leaved Hawthorn | Yes | A1 | 75--35--9 | Ne | Flgg‚ | 0920007256 |
| Crataegus intricata | Lange's Thorn | Clement | A3 | 75--35--int | Lange | 0920006271 | |
| Crataegus laevigata | Midland Hawthorn | Page 25 | A1 | 75--35--8 | N | (Poir.) DC. | 0920000570 |
| Crataegus mollis | Clement | A3 | 75--35--mol | (Torr. & A. Gray) Scheele | 0920006272 | ||
| Crataegus monogyna | Hawthorn | Page 25 | A1 | 75--35--7 | N | Jacq. | 0920000569 |
| Crataegus monogyna x heterophylla | Yes S1 | A1 | 75--35--7 x 9 | 0920003401 | |||
| Crataegus monogyna x laevigata = C. x media | Yes S1 | A1 | 75--35--7 x 8 | N | Bechst. | 0920000568 | |
| Crataegus nigra | Hungarian Thorn | Clement | A3 | 75--35--nig | Waldst. & Kit. | 0920006273 | |
| Crataegus orientalis | Oriental Hawthorn | Yes | A1 | 75--35--10 | Ne | Pall. ex M. Bieb. | 0920007257 |
| Crataegus persimilis | Broad-leaved Cockspurthorn | Yes | A1 | 75--35--5 | Ne | Sarg. | 0920007259 |
| Crataegus punctata | Dotted Hawthorn | Clement | A3 | 75--35--pun | Jacq. | 0920008020 | |
| Crataegus sanguinea | Clement | A3 | 75--35--san | Pall. | 0920006274 | ||
| Crataegus submollis | Hairy Cockspurthorn | Yes | A1 | 75--35--1 | Ne | Sarg. | 0920007260 |
| Crataegus succulenta | Round-fruited Cockspurthorn | Yes | A1 | 75--35--6 | Ne | Schrad. | 0920007261 |
| Crataegus tanacetifolia | Tansy-leaved Thorn | Clement | A3 | 75--35--tan | (Lam.) Pers. | 0920006275 | |
| Crataegus viridis | Southern Thorn | Clement | A3 | 75--35--vir | L. | 0920006276 | |
| Crataegus x lavallei | Hybrid Cockspurthorn | Clement | A3 | 75--35--lav | H‚rincq | 0920006277 | |
| Crepis alpina | Clement | A3 | 135--26--alp | L. | 0920006278 | ||
| Crepis aurea | Golden Hawk's-beard | Clement | A3 | 135--26--aur | (L.) Cass. | 0920006279 | |
| Crepis biennis | Rough Hawk's-beard | Page 25 | A1 | 135--26--3 | N | L. | 0920000571 |
| Crepis capillaris | Smooth Hawk's-beard | Page 25 | A1 | 135--26--4 | N | (L.) Wallr. | 0920000572 |
| Crepis foetida | Stinking Hawk's-beard | Yes | A1 | 135--26--6 | Ar | L. | 0920000573 |
| Crepis foetida subsp. commutata | Clement | A3 | 135--26--6--b | (Spreng.) Babc. | 0920000573.1 | ||
| Crepis foetida subsp. foetida | Other | AT | 135--26--6--a | ||||
| Crepis foetida subsp. rhoeadifolia | Clement | A3 | 135--26--6--c | (M. Bieb.) Schinz & R. Keller | 0920000573.2 | ||
| Crepis mollis | Northern Hawk's-beard | Yes | A1 | 135--26--2 | N | (Jacq.) Asch. | 0920000574 |
| Crepis nicaeensis | French Hawk's-beard | Stace | A2 | 135--26--nic | Ca | Balb. | 0920000575 |
| Crepis paludosa | Marsh Hawk's-beard | Page 25 | A1 | 135--26--1 | N | (L.) Moench | 0920000576 |
| Crepis praemorsa | Leafless Hawk's-beard | Yes | A1 | 135--26--7 | N | (L.) F. Walther | 0920004518 |
| Crepis pulchra | Small-flowered Hawk's-beard | Clement | A3 | 135--26--pul | L. | 0920006282 | |
| Crepis rubra | Pink Hawk's-beard | Clement | A3 | 135--26--rub | L. | 0920005668 | |
| Crepis sancta | Clement | A3 | 135--26--san | (L.) Babc. | 0920006283 | ||
| Crepis setosa | Bristly Hawk's-beard | Stace | A2 | 135--26--set | Ca | Haller f. | 0920000577 |
| Crepis suberostris | Clement | A3 | 135--26--sub | Coss. & Durieu ex Batt. | 0920006284 | ||
| Crepis tectorum | Narrow-leaved Hawk's-beard | Stace | A2 | 135--26--tec | Ca | L. | 0920008021 |
| Crepis vesicaria | Beaked Hawk's-beard | Page 25 | A1 | 135--26--5 | Ne | L. | 0920000578 |
| Crepis vesicaria subsp. taraxacifolia | Yes | A1 | 135--26--5--a | (Thuill.) Thell. ex Schinz & R. Keller | 0920000578 | ||
| Crepis zacintha | Clement | A3 | 135--26--zac | (L.) Babc. | 0920005622 | ||
| Crinum bulbispermum x moorei = C. x powellii | Powell's Cape-lily | Yes S1 | A1 | 158--CRI--bul x moo | Ne | Baker | 0920003405 |
| Crithmum maritimum | Rock Samphire | Page 25 | A1 | 107--17--1 | N | L. | 0920000579 |
| Crithopsis delileana | Clement | A3 | 153--CRI--del | (Schultes) Roshev. | 0920006285 | ||
| Crocosmia masoniorum | Giant Montbretia | Yes | A1 | 159--13--2 | Ne | (L. Bolus) N.E. Br. | 0920007262 |
| Crocosmia masoniorum x pottsii x aurea | Yes S3 | A1 | 159--13--2 x 3 x aur | ||||
| Crocosmia paniculata | Aunt-Eliza | Yes | A1 | 159--13--1 | Ne | (Klatt) Goldblatt | 0920007263 |
| Crocosmia pottsii | Pott's Montbretia | Yes | A1 | 159--13--3 | Ne | (Macnab ex Baker) N.E. Br. | 0920002637 |
| Crocosmia pottsii x aurea = C. x crocosmiiflora | Montbretia | Page 25 | A1 | 159--13--3 x aur | Ne | (Lemoine) N.E. Br. | 0920000580 |
| Crocus ancyrensis | Ankara Crocus | Yes S1 | A1 | 159--8--anc | Ne | (Herb.) Maw | 0920003411 |
| Crocus angustifolius x flavus = C. x stellaris | Yellow Crocus | Yes S1 | A1 | 159--8--fla x ang | Ne | Haw. | 0920003413 |
| Crocus biflorus | Silvery Crocus | Yes S1 | A1 | 159--8--bif | Ne | Mill. | 0920000581 |
| Crocus biflorus subsp. adamii | Yes S1 | A1 | 159--8--bif--a | (J. Gay) B. Mathew | 0920000581 | ||
| Crocus biflorus subsp. biflorus | Yes S2 | A1 | 159--8--bif--b | ||||
| Crocus chrysanthus | Golden Crocus | Yes | A1 | 159--8--6 | Ne | (Herb.) Herb. | 0920007264 |
| Crocus chrysanthus x biflorus | Yes S1 | A1 | 159--8--6 x bif | Ne | 0920003414 | ||
| Crocus kotschyanus | Kotschy's Crocus | Yes | A1 | 159--8--4 | Ne | K. Koch | 0920007265 |
| Crocus longiflorus | Italian Crocus | Yes S1 | A1 | 159--8--lon | Ne | Raf. | 0920003415 |
| Crocus nudiflorus | Autumn Crocus | Yes | A1 | 159--8--3 | Ne | Sm. | 0920000584 |
| Crocus pulchellus | Hairy Crocus | Yes | A1 | 159--8--9 | Ne | Herb. | 0920007266 |
| Crocus sativus | Saffron Crocus | Clement | A3 | 159--8--sat | L. | 0920000585 | |
| Crocus serotinus | Late Crocus | Yes S1 | A1 | 159--8--ser | Ne | Salisb. | 0920003416 |
| Crocus serotinus subsp. salzmannii | Yes S1 | A1 | 159--8--ser--a | (J. Gay) B. Mathew | 0920003416 | ||
| Crocus sieberi | Sieber's Crocus | Yes | A1 | 159--8--5 | Ne | J. Gay | 0920007267 |
| Crocus speciosus | Bieberstein's Crocus | Yes | A1 | 159--8--8 | Ne | M. Bieb. | 0920007268 |
| Crocus tommasinianus | Early Crocus | Yes | A1 | 159--8--2 | Ne | Herb. | 0920005425 |
| Crocus vernus | Spring Crocus | Yes | A1 | 159--8--1 | Ne | (L.) Hill | 0920000582 |
| Crocus vernus subsp. albiflorus | Yes S1 | A1 | 159--8--1--b | (Kit. ex Schult.) Asch. & Graebn. | 0920000582.1 | ||
| Crocus vernus subsp. vernus | Yes S1 | A1 | 159--8--1--a | 0920000582.2 | |||
| Crocus vernus x tommasinianus | Yes S1 | A1 | 159--8--1 x 2 | 0920003417 | |||
| Crocus versicolor | Clement | A3 | 159--8--ver | Ker Gawl. | 0920006286 | ||
| Crucianella angustifolia | Clement | A3 | 130--CRU--ang | L. | 0920004210 | ||
| Crucianella patula | Clement | A3 | 130--CRU--pat | L. | 0920006287 | ||
| Cruciata articulata | Clement | A3 | 130--7--art | (L.) Ehrend. | 0920006288 | ||
| Cruciata laevipes | Crosswort | Page 25 | A1 | 130--7--1 | N | Opiz | 0920000875 |
| Crupina crupinastrum | Clement | A3 | 135--CRU--cru | (Moris) Vis. | 0920006289 | ||
| Crupina vulgaris | False Saw-wort | Clement | A3 | 135--CRU--vul | Cass. | 0920006290 | |
| Crypsis aculeata | Clement | A3 | 153--CRY--acu | (L.) Aiton | 0920006291 | ||
| Crypsis schoenoides | Clement | A3 | 153--CRY--sch | (L.) Lam. | 0920006292 | ||
| Cryptogramma crispa | Parsley Fern | Page 25 | A1 | 7--1--1 | N | (L.) R. Br. ex Hook. | 0910000586 |
| Cryptomeria japonica | Japanese Red-cedar | Yes S2 | A1 | 20A--CRY--jap | Ne | (L. f.) D. Don | 0920002411 |
| Ctenopsis cynosuroides | Clement | A3 | 153--CTE--cyn | (Desf.) Paunero | 0920006293 | ||
| Cucubalus baccifer | Berry Catchfly | Yes | A1 | 46--21--1 | Ne | L. | 0920000587 |
| Cucumis melo | Melon | Stace | A2 | 60--CUC--mel | Ca | L. | 0920008022 |
| Cucumis myriocarpus | Gooseberry Cucumber | Clement | A3 | 60--CUC--myr | Naudin | 0920006294 | |
| Cucumis sativus | Cucumber | Stace | A2 | 60--CUC--sat | Ca | L. | 0920008023 |
| Cucurbita ficifolia | Fig-leaved Gourd | Clement | A3 | 60--CUT--fic | Bouch‚ | 0920006295 | |
| Cucurbita maxima | Pumpkin | Stace | A2 | 60--CUT--max | Ca | Duchesne ex Lam. | 0920008024 |
| Cucurbita pepo | Marrow | Stace | A2 | 60--CUT--pep | Ca | L. | 0920008025 |
| Cuminum cyminum | Cumin | Stace | A2 | 107--CUM--cym | Ca | L. | 0920008026 |
| Cuphea llavea x procumbens = C. x purpurea | Clement | A3 | 81--CUP--lla x flo | hort. ex Lem. | 0920006296 | ||
| Cupressus duclouxiana | Chinese Cypress | Clement | A3 | 21--1--duc | Hickel | 0920003617 | |
| Cupressus goveniana | Californian Cypress | Clement | A3 | 21--1--gov | Gordon | 0920003618 | |
| Cupressus macrocarpa | Monterey Cypress | Yes | A1 | 21--1--1 | Ne | Hartw. ex Gordon | 0920002408 |
| Cupressus macrocarpa x Xanthocyparis nootkatensis = X Cuprocyparis leylandii | Leyland Cypress | Stace | A2 | 21--1 x XAN--1 x XAN | Ne | (A.B. Jacks. & Dallim.) Farjon | |
| Cupressus sempervirens | Italian Cypress | Clement | A3 | 21--1--sem | L. | 0920003620 | |
| Cuscuta americana | Clement | A3 | 112--1--ame | L. | 0920006297 | ||
| Cuscuta approximata | Clement | A3 | 112--1--app | Bab. | 0920006298 | ||
| Cuscuta australis | Australian Dodder | Clement | A3 | 112--1--aus | R. Br. | 0920006299 | |
| Cuscuta campestris | Yellow Dodder | Yes | A1 | 112--1--1 | Ne | Yunck. | 0920004427 |
| Cuscuta epilinum | Flax Dodder | Clement | A3 | 112--1--epi | Weihe | 0920000588 | |
| Cuscuta epithymum | Dodder | Page 25 | A1 | 112--1--3 | N | (L.) L. | 0920000589 |
| Cuscuta europaea | Greater Dodder | Yes | A1 | 112--1--2 | N | L. | 0920000590 |
| Cuscuta planiflora | Clement | A3 | 112--1--pla | Ten. | 0920006300 | ||
| Cuscuta suaveolens | Lucerne Dodder | Clement | A3 | 112--1--sua | Ser. | 0920004249 | |
| Cuspidia cernua | Clement | A3 | 135--CUS--cer | (L. f.) B.L. Burtt | 0920006301 | ||
| Cutandia divaricata | Clement | A3 | 153--CUT--div | (Desf.) Asch. ex Barbey | 0920006302 | ||
| Cutandia maritima | Clement | A3 | 153--CUT--mar | (L.) Barbey | 0920006303 | ||
| Cutandia memphitica | Clement | A3 | 153--CUT--mem | (Spreng.) Benth. | 0920006304 | ||
| Cyanopsis muricata | Clement | A3 | 135--CYA--mur | (L.) Dost l | 0920006305 | ||
| Cyathea dealbata | Silver Tree-fern | Clement | A3 | 11A--CYA--dea | (G. Forst.) Sw. | 0910008027 | |
| Cyclamen coum | Eastern Sowbread | Yes | A1 | 69--3--2 | Ne | Mill. | 0920007269 |
| Cyclamen graecum | Greek Cyclamen | Clement | A3 | 69--3--gra | Link | 0920008028 | |
| Cyclamen hederifolium | Sowbread | Yes | A1 | 69--3--1 | Ne | Aiton | 0920000591 |
| Cyclamen persicum | Florist's Cyclamen | Clement | A3 | 69--3--per | Mill. | 0920006306 | |
| Cyclamen repandum | Spring Sowbread | Yes S1 | A1 | 69--3--rep | Ne | Sibth. & Sm. | 0920008029 |
| Cycloloma atriplicifolium | Winged Pigweed | Clement | A3 | 43--CYC--atr | (Spreng.) Coult. | 0920006307 | |
| Cydonia oblonga | Quince | Yes | A1 | 75--24--1 | Ne | Mill. | 0920007270 |
| Cymbalaria hepaticifolia | Corsican Toadflax | Yes | A1 | 124--11--3 | Ne | (Poir.) Wettst. | 0920007271 |
| Cymbalaria longipes | Clement | A3 | 124--11--lon | (Boiss. & Heldr.) A. Chev. | 0920006308 | ||
| Cymbalaria muralis | Ivy-leaved Toadflax | Page 25 | A1 | 124--11--1 | Ne | P. Gaertn., B. Mey. & Scherb. | 0920000592 |
| Cymbalaria muralis subsp. muralis | Yes | A1 | 124--11--1--a | 0920000592.1 | |||
| Cymbalaria muralis subsp. visianii | Yes | A1 | 124--11--1--b | Ne | (Kmmerle ex J v.) D.A. Webb | 0920000592.2 | |
| Cymbalaria pallida | Italian Toadflax | Yes | A1 | 124--11--2 | Ne | (Ten.) Wettst. | 0920000593 |
| Cynara cardunculus | Globe Artichoke | Yes S1 | A1 | 135--CYN--car | Ne | L. | 0920008030 |
| Cynodon aethiopicus | Clement | A3 | 153--66--aet | Clayton & J.R. Harlan | 0920006309 | ||
| Cynodon dactylon | Bermuda-grass | Yes | A1 | 153--66--1 | ?N | (L.) Pers. | 0920000594 |
| Cynodon incompletus | African Bermuda-grass | Yes | A1 | 153--66--2 | Ca | Nees | 0920007272 |
| Cynodon transvaalensis | Clement | A3 | 153--66--tra | Burtt Davy | 0920006310 | ||
| Cynoglossum amabile | Chinese Hound's-tongue | Clement | A3 | 116--17--ama | Stapf & Drumm. | 0920005669 | |
| Cynoglossum australe | Australian Hound's-tongue | Clement | A3 | 116--17--aus | R. Br. | 0920006311 | |
| Cynoglossum germanicum | Green Hound's-tongue | Yes | A1 | 116--17--2 | N | Jacq. | 0920000595 |
| Cynoglossum montanum | Clement | A3 | 116--17--mon | L. | 0920006312 | ||
| Cynoglossum nervosum | Himalayan Hound's-tongue | Clement | A3 | 116--17--ner | Benth. ex Hook. f. | 0920006313 | |
| Cynoglossum officinale | Hound's-tongue | Page 25 | A1 | 116--17--1 | N | L. | 0920000596 |
| Cynoglottis barrelieri | False Alkanet | Yes | A1 | 116--7--1 | Ne | (All.) Vural & Kit Tan | 0920007273 |
| Cynosurus cristatus | Crested Dog's-tail | Page 25 | A1 | 153--15--1 | N | L. | 0920000597 |
| Cynosurus echinatus | Rough Dog's-tail | Yes | A1 | 153--15--2 | Ne | L. | 0920000598 |
| Cynosurus elegans | Clement | A3 | 153--15--ele | Desf. | 0920006314 | ||
| Cyperus albostriatus | Clement | A3 | 152--11--alb | Schrad. | 0920006315 | ||
| Cyperus brevifolius | Globe Kyllinga | Clement | A3 | 152--11--bre | (Rottb.) Endl. ex Hassk. | 0920006316 | |
| Cyperus clarus | Clement | A3 | 152--11--cla | S.T. Blake | 0920006317 | ||
| Cyperus congestus | Dense Flat-sedge | Clement | A3 | 152--11--con | J. Vahl | 0920006318 | |
| Cyperus cyperinus | Clement | A3 | 152--11--cyp | (Retz.) Suringar | 0920006319 | ||
| Cyperus dactylotes | Clement | A3 | 152--11--dac | Benth. | 0920006320 | ||
| Cyperus difformis | Variable Flat-sedge | Clement | A3 | 152--11--dif | L. | 0920006321 | |
| Cyperus eragrostis | Pale Galingale | Yes | A1 | 152--11--2 | Ne | Lam. | 0920007274 |
| Cyperus erectus | Clement | A3 | 152--11--ere | (Schumach.) Mattf. & Kk. | 0920006322 | ||
| Cyperus esculentus | Yellow Nutsedge | Clement | A3 | 152--11--esc | L. | 0920006323 | |
| Cyperus flavus | Cayenne Cyperus | Clement | A3 | 152--11--fla | (J. Vahl) Boeck. | 0920006324 | |
| Cyperus fuscus | Brown Galingale | Yes | A1 | 152--11--3 | N | L. | 0920000599 |
| Cyperus globulosus | Baldwin's Cyperus | Clement | A3 | 152--11--glo | Aubl. | 0920006325 | |
| Cyperus gunnii | Flecked Flat-sedge | Clement | A3 | 152--11--gun | Hook. f. | 0920006326 | |
| Cyperus involucratus | Clement | A3 | 152--11--inv | Rottb. | 0920004145 | ||
| Cyperus longus | Galingale | Yes | A1 | 152--11--1 | N | L. | 0920000600 |
| Cyperus longus subsp. longus | Other | AT | 152--11--1--a | ||||
| Cyperus longus subsp. tenuiflorus | Clement | A3 | 152--11--1--b | (Rottb.) Kk. | 0920000600.1 | ||
| Cyperus luzulae | Clement | A3 | 152--11--luz | (L.) Retz. | 0920006328 | ||
| Cyperus ovularis | Globose Cyperus | Clement | A3 | 152--11--ovu | (Michx.) Torr. | 0920006329 | |
| Cyperus reflexus | Clement | A3 | 152--11--ref | J. Vahl | 0920006330 | ||
| Cyperus rigidifolius | Clement | A3 | 152--11--rig | Steud. | 0920006331 | ||
| Cyperus rotundus | Purple Nutsedge | Clement | A3 | 152--11--rot | L. | 0920006332 | |
| Cyperus rutilans | Clement | A3 | 152--11--rut | (C.B. Clarke) Maiden & Betche | 0920006333 | ||
| Cyperus sesquiflorus | Clement | A3 | 152--11--ses | (Torr.) Mattf. & Kk. | 0920006334 | ||
| Cyperus sporobolus | Clement | A3 | 152--11--spo | R. Br. | 0920006335 | ||
| Cyperus tenuis | Clement | A3 | 152--11--ten | Sw. | 0920006336 | ||
| Cyperus ustulatus | Giant Umbrella-sedge | Clement | A3 | 152--11--ust | A. Rich. | 0920006337 | |
| Cyperus vaginatus | Stiff-leaved Flat-sedge | Clement | A3 | 152--11--vag | R. Br. | 0920006338 | |
| Cyphomandra crassicaulis | Tree Tomato | Clement | A3 | 110--CYP--cra | (Ortega) Kuntze | 0920006339 | |
| Cypripedium calceolus | Lady's-slipper | Yes | A1 | 162--1--1 | N | L. | 0920000601 |
| Cyrtanthus elatus | Scarborough Lily | Clement | A3 | 158--CYR--ela | (Jacq.) Traub | 0920006340 | |
| Cyrtomium falcatum | House Holly-fern | Yes | A1 | 17--2--1 | Ne | (L. f.) C. Presl | 0910002502 |
| Cystopteris alpina | Alpine Bladder-fern | Yes S3 | A1 | 16--5--alp | (Lam.) Desv. | ||
| Cystopteris diaphana | Greenish Bladder-fern | Yes S3 | A1 | 16--5--dia | (Bory) Blasdell | ||
| Cystopteris dickieana | Dickie's Bladder-fern | Yes | A1 | 16--5--2 | N | R. Sim | 0910000602 |
| Cystopteris fragilis | Brittle Bladder-fern | Page 25 | A1 | 16--5--1 | N | (L.) Bernh. | 0910000603 |
| Cystopteris montana | Mountain Bladder-fern | Yes | A1 | 16--5--3 | N | (Lam.) Desv. | 0910000604 |
| Cytisus battandieri | Pineapple Broom | Clement | A3 | 77--23--bat | Maire | 0920006341 | |
| Cytisus multiflorus | White Broom | Yes | A1 | 77--23--2 | Ne | (L'H‚r.) Sweet | 0920007275 |
| Cytisus nigricans | Black Broom | Yes | A1 | 77--23--1 | Ne | L. | 0920007276 |
| Cytisus scoparius | Broom | Page 25 | A1 | 77--23--4 | N | (L.) Link | 0920001822 |
| Cytisus scoparius subsp. maritimus | Prostrate Broom | Yes | A1 | 77--23--4--b | N | (Rouy) Heywood | 0920001822.1 |
| Cytisus scoparius subsp. scoparius | Yes | A1 | 77--23--4--a | 0920001822.2 | |||
| Cytisus striatus | Hairy-fruited Broom | Yes | A1 | 77--23--3 | Ne | (Hill) Rothm. | 0920002645 |