| citrus latifolia | Yes | species | eukaryota | plants | species | 200541 | click here |
| citrus limon | Yes | species | eukaryota | plants | species | 2708 | click here |
| citrus maxima | Yes | species | eukaryota | plants | species | 37334 | click here |
| citrus reticulata | Yes | species | eukaryota | plants | species | 85571 | click here |
| citrus sinensis | Yes | species | eukaryota | plants | species | 2711 | click here |
| citrus x paradisi | Yes | subspecies | eukaryota | plants | species | 37656 | click here |
| cixius | Yes | | | invertebrates | genus | 130546 | click here |
| cixius wagneri | Yes | species | eukaryota | invertebrates | species | 472720 | click here |
| clematis vitalba | Yes | species | eukaryota | plants | species | 37490 | click here |
| cleome | Yes | | | plants | genus | 25782 | click here |
| cleome gynandra | Yes | species | eukaryota | plants | species | 190802 | click here |
| cleome rutidosperma | Yes | species | eukaryota | plants | species | 190803 | click here |
| coccinia grandis | Yes | species | eukaryota | plants | species | 387127 | click here |
| cocos nucifera | Yes | species | eukaryota | plants | species | 13894 | click here |
| codiaeum variegatum | Yes | species | eukaryota | plants | species | 138558 | click here |
| coffea arabica | Yes | species | eukaryota | plants | species | 13443 | click here |
| coix lacryma-jobi | Yes | no rank | eukaryota | plants | species | 4505 | click here |
| colladonus montanus | Yes | species | | | species | 1863043 | click here |
| conium maculatum | Yes | species | eukaryota | plants | species | 13447 | click here |
| conocarpus erectus | Yes | species | eukaryota | plants | species | 134917 | click here |
| convolvulus arvensis | Yes | species | eukaryota | plants | species | 4123 | click here |
| convolvulus auricomus | Yes | species | eukaryota | plants | species | 267586 | click here |
| convolvulus cneorum | Yes | species | eukaryota | plants | species | 267577 | click here |
| convolvulus virgatus | Yes | species | | | species | 1428878 | click here |
| conyza bonariensis | Yes | species | eukaryota | plants | species | 91242 | click here |
| conyza canadensis | Yes | species | eukaryota | plants | species | 72917 | click here |
| corchorus aestuans | Yes | species | eukaryota | plants | species | 360610 | click here |
| corchorus capsularis | Yes | species | eukaryota | plants | species | 210143 | click here |
| corchorus olitorius | Yes | species | eukaryota | plants | species | 93759 | click here |
| cornus | Yes | | | plants | genus | 4281 | click here |
| cornus racemosa | Yes | species | eukaryota | plants | species | 4284 | click here |
| corylus avellana | Yes | species | eukaryota | plants | species | 13451 | click here |
| corynandra viscosa | Yes | species | eukaryota | plants | species | 190804 | click here |
| cosmos bipinnatus | Yes | species | eukaryota | plants | species | 51277 | click here |
| crassostrea gigas | Yes | species | eukaryota | invertebrates | species | 29159 | click here |
| crataegus monogyna | Yes | species | eukaryota | plants | species | 140997 | click here |
| creontiades pallidus | Yes | species | | | species | 1996564 | click here |
| crepis biennis | Yes | species | eukaryota | plants | species | 122532 | click here |
| crepis foetida | Yes | species | eukaryota | plants | species | 268017 | click here |
| crossandra infundibuliformis | Yes | species | eukaryota | plants | species | 76280 | click here |
| crotalaria | Yes | | | plants | genus | 3828 | click here |
| crotalaria cytisoides | Yes | species | | | species | 452831 | click here |
| crotalaria goreensis | Yes | species | eukaryota | plants | species | 165767 | click here |
| crotalaria juncea | Yes | species | eukaryota | plants | species | 3829 | click here |
| crotalaria pallida | Yes | species | eukaryota | plants | species | 3830 | click here |
| crotalaria retusa | Yes | species | eukaryota | plants | species | 165774 | click here |
| crotalaria saltiana | Yes | species | | | species | 1151068 | click here |
| crotalaria spectabilis | Yes | species | eukaryota | plants | species | 517187 | click here |
| crotalaria trichotoma | Yes | species | eukaryota | plants | species | 452830 | click here |
| croton | Yes | | | plants | genus | 100370 | click here |
| croton bonplandianus | Yes | species | eukaryota | plants | species | 323030 | click here |
| cryptotaenia japonica | Yes | species | eukaryota | plants | species | 48117 | click here |
| ctenarytaina eucalypti | Yes | species | eukaryota | invertebrates | species | 121841 | click here |
| ctenarytaina spatulata | Yes | species | eukaryota | invertebrates | species | 121843 | click here |
| cucumis myriocarpus | Yes | species | eukaryota | plants | species | 39474 | click here |
| cucumis sativus | Yes | species | eukaryota | plants | species | 3659 | click here |
| cucurbita | Yes | | | plants | genus | 3660 | click here |
| cucurbita maxima | Yes | species | eukaryota | plants | species | 3661 | click here |
| cucurbita moschata | Yes | species | eukaryota | plants | species | 3662 | click here |
| cucurbita pepo | Yes | species | eukaryota | plants | species | 3663 | click here |
| culex nigripalpus | Yes | species | eukaryota | invertebrates | species | 42429 | click here |
| culicoides arakawae | Yes | species | eukaryota | invertebrates | species | 198116 | click here |
| culicoides sonorensis | Yes | species | eukaryota | invertebrates | species | 179676 | click here |
| cupressus sempervirens | Yes | species | eukaryota | plants | species | 13469 | click here |
| cyanthillium cinereum | Yes | species | eukaryota | plants | species | 211151 | click here |
| cycas | Yes | | | plants | genus | 3395 | click here |
| cycas revoluta | Yes | species | eukaryota | plants | species | 3396 | click here |
| cydonia oblonga | Yes | species | eukaryota | plants | species | 36610 | click here |
| cynodon dactylon | Yes | species | eukaryota | plants | species | 28909 | click here |
| cyperus | Yes | | | plants | genus | 4610 | click here |
| cyperus esculentus | Yes | species | | | species | 1053340 | click here |
| cyperus rotundus | Yes | species | eukaryota | plants | species | 512623 | click here |
| cyrtostachys renda | Yes | species | eukaryota | plants | species | 131265 | click here |
| dactylis glomerata | Yes | species | eukaryota | plants | species | 4509 | click here |
| dahlia pinnata | Yes | species | eukaryota | plants | species | 101596 | click here |
| dalbulus elimatus | Yes | species | eukaryota | invertebrates | species | 74070 | click here |
| dalbulus maidis | Yes | species | eukaryota | invertebrates | species | 74065 | click here |
| datura | Yes | | | plants | genus | 4074 | click here |
| datura inoxia | Yes | species | eukaryota | plants | species | 4075 | click here |
| datura metel | Yes | species | eukaryota | plants | species | 35625 | click here |
| datura stramonium | Yes | species | eukaryota | plants | species | 4076 | click here |
| daucus carota | Yes | species | eukaryota | plants | species | 4039 | click here |
| daucus carota subsp. sativus | Yes | subspecies | eukaryota | plants | subspecies | 79200 | click here |
| delphinium | Yes | | | plants | genus | 46246 | click here |
| demodex ursi | Yes | species | | | species | 1284200 | click here |
| dendrocalamus strictus | Yes | species | eukaryota | plants | species | 231030 | click here |
| desmodium heterocarpon | Yes | species | eukaryota | plants | species | 499991 | click here |
| dianthus | Yes | | | plants | genus | 3569 | click here |
| dianthus barbatus | Yes | species | eukaryota | plants | species | 278075 | click here |
| dianthus caryophyllus | Yes | species | eukaryota | plants | species | 3570 | click here |
| dianthus chinensis | Yes | species | eukaryota | plants | species | 118431 | click here |
| diaphorina citri | Yes | species | eukaryota | invertebrates | species | 121845 | click here |
| dichanthium annulatum | Yes | species | eukaryota | plants | species | 106888 | click here |
| dictyophara europaea | Yes | species | | | species | 1240369 | click here |
| digitaria | Yes | | | plants | genus | 66017 | click here |
| digitaria ciliaris | Yes | species | eukaryota | plants | species | 66018 | click here |
| digitaria sanguinalis | Yes | species | eukaryota | plants | species | 121769 | click here |
| dimocarpus longan | Yes | species | eukaryota | plants | species | 128017 | click here |
| dioscorea oppositifolia | Yes | species | eukaryota | plants | species | 569628 | click here |
| diospyros kaki | Yes | species | eukaryota | plants | species | 35925 | click here |