| bursaphelenchus xylophilus | Yes | species | eukaryota | invertebrates | species | 6326 | click here | 
| cajanus cajan | Yes | species | eukaryota | plants | species | 3821 | click here | 
| calicotome | Yes |   |   | plants | genus | 49798 | click here | 
| calicotome spinosa | Yes | species | eukaryota | plants | species | 194235 | click here | 
| calicotome villosa | Yes | species | eukaryota | plants | species | 49799 | click here | 
| calliandra calothyrsus | Yes | species |   |   | species | 560018 | click here | 
| calliandra surinamensis | Yes | species | eukaryota | plants | species | 204986 | click here | 
| calobota saharae | Yes | species | eukaryota | plants | species | 449091 | click here | 
| calyptra thalictri | Yes | species | eukaryota | invertebrates | species | 465833 | click here | 
| canavalia | Yes |   |   | plants | genus | 3822 | click here | 
| canavalia gladiata | Yes | species | eukaryota | plants | species | 3824 | click here | 
| canna flaccida | Yes | species | eukaryota | plants | species | 147184 | click here | 
| cannabis sativa | Yes | species | eukaryota | plants | species | 3483 | click here | 
| capsicum | Yes |   |   | plants | genus | 4071 | click here | 
| capsicum annuum | Yes | species | eukaryota | plants | species | 4072 | click here | 
| capsicum annuum var. annuum | Yes | varietas | eukaryota | plants | varietas | 40321 | click here | 
| capsicum frutescens | Yes | species | eukaryota | plants | species | 4073 | click here | 
| caragana | Yes |   |   | plants | genus | 20483 | click here | 
| caragana korshinskii | Yes | species | eukaryota | plants | species | 220689 | click here | 
| caragana korshinskii var. intermedia | Yes |   | eukaryota | plants | varietas | 220692 | click here | 
| caragana microphylla | Yes | species | eukaryota | plants | species | 220690 | click here | 
| caragana opulens | Yes | species | eukaryota | plants | species | 390498 | click here | 
| caragana pruinosa | Yes | species | eukaryota | plants | species | 390499 | click here | 
| caragana sinica | Yes | species | eukaryota | plants | species | 403832 | click here | 
| caralluma tuberculata | Yes | species | eukaryota | plants | species | 197238 | click here | 
| cardamine cordifolia | Yes | species | eukaryota | plants | species | 558111 | click here | 
| cariniana estrellensis | Yes | species | eukaryota | plants | species | 79561 | click here | 
| carmichaelia australis | Yes | species | eukaryota | plants | species | 99010 | click here | 
| catharanthus roseus | Yes | species | eukaryota | plants | species | 4058 | click here | 
| cecropia pachystachya | Yes | species |   |   | species | 1472306 | click here | 
| cenchrus americanus | Yes | species | eukaryota | plants | species | 4543 | click here | 
| cenchrus ciliaris | Yes | species | eukaryota | plants | species | 35872 | click here | 
| centaurea horrida | Yes | species |   |   | species | 668807 | click here | 
| centrolobium paraense | Yes | species | eukaryota | plants | species | 500179 | click here | 
| centrosema pubescens | Yes | species | eukaryota | plants | species | 185703 | click here | 
| chamaecrista pumila | Yes | species |   |   | species | 1526916 | click here | 
| cheliomyrmex | Yes |   |   | invertebrates | genus | 232176 | click here | 
| chidlowia sanguinea | Yes | species |   |   | species | 1200356 | click here | 
| chloroleucon tortum | Yes | species |   |   | species | 560027 | click here | 
| chrysanthemum | Yes |   |   | plants | genus | 13422 | click here | 
| chrysanthemum sp. | Yes | no rank | eukaryota | plants | species | 137606 | click here | 
| chrysanthemum x morifolium | Yes | subspecies | eukaryota | plants | species | 41568 | click here | 
| cicer arietinum | Yes | species | eukaryota | plants | species | 3827 | click here | 
| cicer canariense | Yes | species | eukaryota | plants | species | 200948 | click here | 
| cicer pinnatifidum | Yes | species | eukaryota | plants | species | 47088 | click here | 
| citrus | Yes |   |   | plants | genus | 2706 | click here | 
| citrus aurantiifolia | Yes | species | eukaryota | plants | species | 159033 | click here | 
| citrus sinensis | Yes | species | eukaryota | plants | species | 2711 | click here | 
| citrus x paradisi | Yes | subspecies | eukaryota | plants | species | 37656 | click here | 
| clianthus puniceus | Yes | species | eukaryota | plants | species | 20511 | click here | 
| clitoria fairchildiana | Yes | species |   |   | species | 560020 | click here | 
| clitoria ternatea | Yes | species | eukaryota | plants | species | 43366 | click here | 
| coffea canephora | Yes | species | eukaryota | plants | species | 49390 | click here | 
| colophospermum mopane | Yes | species | eukaryota | plants | species | 162715 | click here | 
| colostethus panamansis | Yes | species | eukaryota | vertebrates | species | 384868 | click here | 
| colutea arborescens | Yes | species | eukaryota | plants | species | 47649 | click here | 
| corynorhinus townsendii | Yes | species | eukaryota | mammals | species | 124745 | click here | 
| craugastor crassidigitus | Yes | species | eukaryota | vertebrates | species | 228433 | click here | 
| crotalaria | Yes |   |   | plants | genus | 3828 | click here | 
| crotalaria burhia | Yes | species |   |   | species | 1117112 | click here | 
| crotalaria ferruginea | Yes | species |   |   | species | 1978205 | click here | 
| crotalaria incana | Yes | species | eukaryota | plants | species | 46447 | click here | 
| crotalaria juncea | Yes | species | eukaryota | plants | species | 3829 | click here | 
| crotalaria pallida | Yes | species | eukaryota | plants | species | 3830 | click here | 
| crotalaria pumila | Yes | species | eukaryota | plants | species | 247889 | click here | 
| crotalaria spectabilis | Yes | species | eukaryota | plants | species | 517187 | click here | 
| crotalaria spinosa | Yes | species |   |   | species | 1232590 | click here | 
| cucumis melo | Yes | species | eukaryota | plants | species | 3656 | click here | 
| cucumis sativus | Yes | species | eukaryota | plants | species | 3659 | click here | 
| culicidae | Yes |   |   | invertebrates | family | 7157 | click here | 
| cullen corylifolium | Yes | species | eukaryota | plants | species | 429560 | click here | 
| cuminum cyminum | Yes | species | eukaryota | plants | species | 52462 | click here | 
| curcuma longa | Yes | species | eukaryota | plants | species | 136217 | click here | 
| cyamopsis tetragonoloba | Yes | species | eukaryota | plants | species | 3832 | click here | 
| cycas revoluta | Yes | species | eukaryota | plants | species | 3396 | click here | 
| cyclopia plicata | Yes | species | eukaryota | plants | species | 384658 | click here | 
| cyclopia pubescens | Yes | species | eukaryota | plants | species | 155108 | click here | 
| cyclopia sessiliflora | Yes | species | eukaryota | plants | species | 337842 | click here | 
| cymbidium faberi | Yes | species | eukaryota | plants | species | 112604 | click here | 
| cymbidium goeringii | Yes | species | eukaryota | plants | species | 112607 | click here | 
| cyperus rotundus | Yes | species | eukaryota | plants | species | 512623 | click here | 
| cytisus scoparius | Yes | species | eukaryota | plants | species | 3835 | click here | 
| cytisus striatus | Yes | species | eukaryota | plants | species | 176342 | click here | 
| cytisus supranubius | Yes | species | eukaryota | plants | species | 49845 | click here | 
| dalbergia | Yes |   |   | plants | genus | 53862 | click here | 
| dalbergia hupeana | Yes | species | eukaryota | plants | species | 53863 | click here | 
| dalbergia miscolobium | Yes | species | eukaryota | plants | species | 397178 | click here | 
| dalbergia odorifera | Yes | species | eukaryota | plants | species | 499988 | click here | 
| dalea leporina | Yes | species | eukaryota | plants | species | 457896 | click here | 
| daphnia pulex | Yes | species | eukaryota | invertebrates | species | 6669 | click here | 
| dasyatis sabina | Yes | species | eukaryota | vertebrates | species | 79690 | click here | 
| daviesia leptophylla | Yes | species | eukaryota | plants | species | 233825 | click here | 
| dendrobates auratus | Yes | species | eukaryota | vertebrates | species | 43471 | click here | 
| dendrobium moschatum | Yes | species | eukaryota | plants | species | 117955 | click here | 
| derris elliptica | Yes | species | eukaryota | plants | species | 56063 | click here | 
| derris trifoliata | Yes | species | eukaryota | plants | species | 185716 | click here | 
| desmanthus illinoensis | Yes | species | eukaryota | plants | species | 196648 | click here | 
| desmanthus paspalaceus | Yes | species | eukaryota | plants | species | 196654 | click here | 
| desmanthus virgatus | Yes | species | eukaryota | plants | species | 196661 | click here | 
| desmodium barbatum | Yes | species | eukaryota | plants | species | 556501 | click here |