| campsis radicans | Yes | species | eukaryota | plants | species | 83937 | click here |
| camptotheca acuminata | Yes | species | eukaryota | plants | species | 16922 | click here |
| campuloclinium macrocephalum | Yes | species | eukaryota | plants | species | 287724 | click here |
| campyloneurum angustifolium | Yes | species | eukaryota | plants | species | 187342 | click here |
| campyloneurum phyllitidis | Yes | species | eukaryota | plants | species | 424520 | click here |
| cananga odorata | Yes | species | eukaryota | plants | species | 13393 | click here |
| canavalia ensiformis | Yes | species | eukaryota | plants | species | 3823 | click here |
| canavalia gladiata | Yes | species | eukaryota | plants | species | 3824 | click here |
| canidae | Yes | | | mammals | family | 9608 | click here |
| canis lupus familiaris | Yes | subspecies | eukaryota | mammals | subspecies | 9615 | click here |
| cannabis | Yes | | | plants | genus | 3482 | click here |
| cannabis sativa | Yes | species | eukaryota | plants | species | 3483 | click here |
| capparis spinosa | Yes | species | eukaryota | plants | species | 65558 | click here |
| capra hircus | Yes | species | eukaryota | mammals | species | 9925 | click here |
| capsella bursa-pastoris | Yes | no rank | eukaryota | plants | species | 3719 | 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 chinense | Yes | species | eukaryota | plants | species | 80379 | click here |
| capsicum frutescens | Yes | species | eukaryota | plants | species | 4073 | click here |
| caragana | Yes | | | plants | genus | 20483 | click here |
| caragana arborescens | Yes | species | eukaryota | plants | species | 20484 | click here |
| caragana frutex | Yes | species | eukaryota | plants | species | 47643 | click here |
| caragana microphylla | Yes | species | eukaryota | plants | species | 220690 | click here |
| caragana versicolor | Yes | species | eukaryota | plants | species | 626697 | click here |
| carallia brachiata | Yes | species | eukaryota | plants | species | 61141 | click here |
| carapa guianensis | Yes | species | eukaryota | plants | species | 201012 | click here |
| cardamine hirsuta | Yes | species | eukaryota | plants | species | 50463 | click here |
| carduus | Yes | | | plants | genus | 92905 | click here |
| carex | Yes | | | plants | genus | 13398 | click here |
| carex acutiformis | Yes | species | eukaryota | plants | species | 140783 | click here |
| carex appressa var. virgata | Yes | varietas | eukaryota | plants | varietas | 291498 | click here |
| carex aquatilis var. dives | Yes | varietas | eukaryota | plants | varietas | 657465 | click here |
| carex firma | Yes | species | eukaryota | plants | species | 140813 | click here |
| carex gigantea | Yes | species | | | species | 912433 | click here |
| carex hoodii | Yes | species | eukaryota | plants | species | 240669 | click here |
| carex pendula | Yes | species | eukaryota | plants | species | 312760 | click here |
| carex rostrata | Yes | species | eukaryota | plants | species | 241230 | click here |
| carex scabrifolia | Yes | species | eukaryota | plants | species | 538521 | click here |
| carex secalina | Yes | species | eukaryota | plants | species | 262043 | click here |
| carex stenophylla | Yes | species | eukaryota | plants | species | 240667 | click here |
| carica papaya | Yes | species | eukaryota | plants | species | 3649 | click here |
| cariniana estrellensis | Yes | species | eukaryota | plants | species | 79561 | click here |
| carollia perspicillata | Yes | species | eukaryota | mammals | species | 40233 | click here |
| caroxylon imbricatum | Yes | species | | | species | 1194693 | click here |
| caroxylon passerinum | Yes | species | eukaryota | plants | species | 151258 | click here |
| caroxylon vermiculatum | Yes | species | eukaryota | plants | species | 240111 | click here |
| carpentaria acuminata | Yes | species | eukaryota | plants | species | 292695 | click here |
| carpinus | Yes | | | plants | genus | 12989 | click here |
| carpinus betulus | Yes | species | eukaryota | plants | species | 12990 | click here |
| carpinus laxiflora | Yes | species | eukaryota | plants | species | 78631 | click here |
| carpinus orientalis | Yes | species | eukaryota | plants | species | 175951 | click here |
| carpinus tschonoskii | Yes | species | eukaryota | plants | species | 139404 | click here |
| carpobrotus | Yes | | | plants | genus | 141999 | click here |
| carpophilus corticinus | Yes | species | eukaryota | invertebrates | species | 913115 | click here |
| carthamus tinctorius | Yes | species | eukaryota | plants | species | 4222 | click here |
| carum carvi | Yes | species | eukaryota | plants | species | 48032 | click here |
| carya | Yes | | | plants | genus | 13402 | click here |
| carya cathayensis | Yes | species | eukaryota | plants | species | 139927 | click here |
| carya cordiformis | Yes | species | eukaryota | plants | species | 139928 | click here |
| carya illinoinensis | Yes | species | eukaryota | plants | species | 32201 | click here |
| caryophyllaceae | Yes | | | plants | family | 3568 | click here |
| caryota | Yes | | | plants | genus | 4713 | click here |
| caryota mitis | Yes | species | eukaryota | plants | species | 4714 | click here |
| caryota urens | Yes | species | eukaryota | plants | species | 561305 | click here |
| cassia | Yes | | | plants | genus | 53851 | click here |
| cassia fistula | Yes | species | eukaryota | plants | species | 53852 | click here |
| castanea | Yes | | | plants | genus | 21019 | click here |
| castanea crenata | Yes | species | eukaryota | plants | species | 103480 | click here |
| castanea dentata | Yes | species | eukaryota | plants | species | 134033 | click here |
| castanea mollissima | Yes | species | eukaryota | plants | species | 60419 | click here |
| castanea sativa | Yes | species | eukaryota | plants | species | 21020 | click here |
| castanopsis | Yes | | | plants | genus | 114815 | click here |
| castanopsis fargesii | Yes | species | eukaryota | plants | species | 167386 | click here |
| castanopsis indica | Yes | species | eukaryota | plants | species | 167391 | click here |
| castanopsis sieboldii | Yes | species | eukaryota | plants | species | 115717 | click here |
| castilleja miniata | Yes | species | eukaryota | plants | species | 48552 | click here |
| castor | Yes | | | rodents | genus | 10184 | click here |
| casuarina | Yes | | | plants | genus | 3521 | click here |
| casuarina cunninghamiana | Yes | species | eukaryota | plants | species | 29737 | click here |
| casuarina equisetifolia | Yes | species | eukaryota | plants | species | 3523 | click here |
| catalpa bignonioides | Yes | species | eukaryota | plants | species | 85179 | click here |
| catalpa bungei | Yes | species | eukaryota | plants | species | 265496 | click here |
| catalpa ovata | Yes | species | eukaryota | plants | species | 265497 | click here |
| catalpa speciosa | Yes | species | eukaryota | plants | species | 155717 | click here |
| catananche caerulea | Yes | species | eukaryota | plants | species | 114285 | click here |
| catharanthus roseus | Yes | species | eukaryota | plants | species | 4058 | click here |
| catocala piatrix | Yes | species | eukaryota | invertebrates | species | 500500 | click here |
| cattleya | Yes | | | plants | genus | 38236 | click here |
| cattleya brevipedunculata | Yes | species | eukaryota | plants | species | 123203 | click here |
| cattleya hybrid cultivar | Yes | species | | | species | 1101197 | click here |
| cattleya milleri | Yes | species | eukaryota | plants | species | 142405 | click here |
| catunaregam spinosa | Yes | species | eukaryota | plants | species | 136894 | click here |
| catunaregam tomentosa | Yes | species | | | species | 907773 | click here |
| caularthron bilamellatum | Yes | species | eukaryota | plants | species | 123130 | click here |
| caulerpa racemosa | Yes | species | eukaryota | plants | species | 76317 | click here |
| caulerpa taxifolia | Yes | species | eukaryota | plants | species | 76313 | click here |
| cecropia insignis | Yes | species | eukaryota | plants | species | 241854 | click here |
| cecropia longipes | Yes | species | eukaryota | plants | species | 681420 | click here |
| cecropia peltata | Yes | species | eukaryota | plants | species | 210352 | click here |