| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| JACA4 | Jaumea carnosa (Less.) Gray | marsh jaumea | Asteraceae
|
| JAUME | Jaumea Pers. | jaumea | Asteraceae
|
| JEBR | Jefea brevifolia (Gray) Stother | shortleaf jefea | Asteraceae
|
| JEFEA | Jefea Stother | jefea | Asteraceae
|
| JEDI | Jeffersonia diphylla (L.) Pers. | twinleaf | Berberidaceae
|
| JEFFE | Jeffersonia W. Bart. | jeffersonia | Berberidaceae
|
| JEHE | Jepsonia heterandra Eastw. | foothill jepsonia | Saxifragaceae
|
| JEMA | Jepsonia malvifolia (Greene) Small | island jepsonia | Saxifragaceae
|
| JEPA | Jepsonia parryi (Torr.) Small | Parry's jepsonia | Saxifragaceae
|
| JEPSO | Jepsonia Small | jepsonia | Saxifragaceae
|
| JOAS | Joinvillea ascendens Gaud. ex Brongn. & Gris | 'ohe | Joinvilleaceae
|
| JOINV | Joinvillea Gaud. ex Brongn. & Gris | joinvillea | Joinvilleaceae
|
| JOHE | Jovibarba heuffelii (Schott) A.& D. L�ve | hen and chickens | Crassulaceae
|
| JOVIB | Jovibarba Opiz | jovibarba | Crassulaceae
|
| JUCH3 | Jubaea chilensis (Molina) Baillon | Chile cocopalm | Arecaceae
|
| JUBAE | Jubaea Kunth | jubaea | Arecaceae
|
| JUPE7 | Jubula pensylvanica (Steph.) A. Evans | | Jubulaceae
|
| JUBUL | Jubula Dumort. nom. cons. | | Jubulaceae
|
| JUAI | Juglans ailanthifolia Carr. | Japanese walnut | Juglandaceae
|
| JUAI2 | Juglans ailantifolia Carriere | Japanese walnut | Juglandaceae
|
| JUAL5 | Juglans alba L. p.p. | Carya alba | Juglandaceae
|
| JUBI3 | Juglans �bixbyi Rehd. | | Juglandaceae
|
| JUBO4 | Juglans boliviana (C. DC.) Dode | Bolivian walnut | Juglandaceae
|
| JUCAH | Juglans californica S. Wats. var. hindsii Jepson | Juglans hindsii | Juglandaceae
|
| JUCA | Juglans californica S. Wats. | Southern California walnut | Juglandaceae
|
| JUCI | Juglans cinerea L. | butternut | Juglandaceae
|
| JUEL2 | Juglans elaeopyren Dode | Juglans major | Juglandaceae
|
| JUHI | Juglans hindsii (Jepson) Jepson ex R.E. Sm. | Northern California walnut | Juglandaceae
|
| JUHO3 | Juglans honorei Dode | Juglans neotropica | Juglandaceae
|
| JUIN3 | Juglans �intermedia Carr. | | Juglandaceae
|
| JUJA | Juglans jamaicensis C. DC. | West Indian walnut | Juglandaceae
|
| JUMA | Juglans major (Torr.) Heller | Arizona walnut | Juglandaceae
|
| JUMIM2 | Juglans microcarpa Berl. var. major (Torr.) L. Benson | Juglans major | Juglandaceae
|
| JUMIM | Juglans microcarpa Berl. var. microcarpa | little walnut | Juglandaceae
|
| JUMIS | Juglans microcarpa Berl. var. stewartii (I.M. Johnston) W. Manning | Stewart's little walnut | Juglandaceae
|
| JUMI | Juglans microcarpa Berl. | little walnut | Juglandaceae
|
| JUNE5 | Juglans neotropica Diels | Andean walnut | Juglandaceae
|
| JUNI | Juglans nigra L. | black walnut | Juglandaceae
|
| JUQU | Juglans �quadrangulata (Carr.) Rehd. (pro sp.) | | Juglandaceae
|
| JURE80 | Juglans regia L. | English walnut | Juglandaceae
|
| JURUM | Juglans rupestris Engelm. ex Torr. var. major Torr. | Juglans major | Juglandaceae
|
| JURU4 | Juglans rupestris Engelm. ex Torr. | Juglans microcarpa var. microcarpa | Juglandaceae
|
| JUSI2 | Juglans sieboldiana Maxim. | Juglans ailanthifolia | Juglandaceae
|
| JUGLA | Juglans L. | walnut | Juglandaceae
|
| JUAS3 | Julella asema R. C. Harris | | Thelenellaceae
|
| JUDI5 | Julella dispora (Mull. Arg.) R. C. Harris | | Thelenellaceae
|
| JUFA3 | Julella fallaciosa (Arnold) R. C. Harris | | Thelenellaceae
|
| JUGE3 | Julella geminella (Nyl.) R. C. Harris | | Thelenellaceae
|
| JULA4 | Julella lactea (A. Massal.) M. E. Barr | | Thelenellaceae
|
| JUSU9 | Julella sublactea (Nyl.) R. C. Harris | | Thelenellaceae
|
| JUTA | Julella taxodii R. C. Harris | | Thelenellaceae
|
| JUVA3 | Julella variiformis R. C. Harris | | Thelenellaceae
|
| JUVI2 | Julella vitrispora (Cooke & Harkness) M. E. Barr | | Thelenellaceae
|
| JULEL2 | Julella J. H. C. Fabre | julella | Thelenellaceae
|
| JUAR | Julocroton argenteus (L.) Didr. | Croton argenteus | Euphorbiaceae
|
| JUSE5 | Juncellus serotinus (Rottb.) Clarke | Cyperus serotinus | Cyperaceae
|
| JUAR5 | Juncoides arcticum (Blytt) Coville | Luzula arctica ssp. arctica | Juncaceae
|
| JUBU3 | Juncoides bulbosum (Wood) Small | Luzula bulbosa | Juncaceae
|
| JUCA12 | Juncoides campestre (L.) Kuntze | Luzula campestris | Juncaceae
|
| JUCA11 | Juncoides carolinae (S. Wats.) Kuntze | Luzula acuminata var. carolinae | Juncaceae
|
| JUEC | Juncoides echinatum Small | Luzula echinata | Juncaceae
|
| JUHY2 | Juncoides hyperboreum (R. Br.) Sheldon p.p. | Luzula arctica ssp. arctica | Juncaceae
|
| JUHY2 | Juncoides hyperboreum (R. Br.) Sheldon p.p. | Luzula confusa | Juncaceae
|
| JUNE3 | Juncoides nemorosum (Pollard) Kuntze | Luzula luzuloides | Juncaceae
|
| JUPA4 | Juncoides parviflorum (Ehrh.) Coville | Luzula parviflora | Juncaceae
|
| JUPI2 | Juncoides piperi Coville | Luzula piperi | Juncaceae
|
| JUSA3 | Juncoides saltuense (Fern.) Heller | Luzula acuminata var. acuminata | Juncaceae
|
| JUSP2 | Juncoides spicatum (L.) Kuntze | Luzula spicata | Juncaceae
|
| JUAB2 | Juncus abjectus F.J. Herm. | Juncus hemiendytus var. abjectus | Juncaceae
|
| JUAB | Juncus abortivus Chapman | annual rush | Juncaceae
|
| JUACR | Juncus acuminatus Michx. var. robustus Engelm. | Juncus nodatus | Juncaceae
|
| JUAC | Juncus acuminatus Michx. | tapertip rush | Juncaceae
|
| JUACL | Juncus acutus L. ssp. leopoldii (Parl.) Snog. | Leopold's rush | Juncaceae
|
| JUACS | Juncus acutus L. var. sphaerocarpus Engelm. | Juncus acutus ssp. leopoldii | Juncaceae
|
| JUAC2 | Juncus acutus L. | spiny rush | Juncaceae
|
| JUAL2 | Juncus albescens (Lange) Fern. | northern white rush | Juncaceae
|
| JUAL3 | Juncus �alpiniformis Fern. | | Juncaceae
|
| JUALA2 | Juncus alpinoarticulatus Chaix ssp. americanus (Farw.) H�met-Ahti | Juncus alpinoarticulatus ssp. nodulosus | Juncaceae
|
| JUALF2 | Juncus alpinoarticulatus Chaix ssp. fuscescens (Fern.) H�met-Ahti | Juncus alpinoarticulatus ssp. nodulosus | Juncaceae
|
| JUALN | Juncus alpinoarticulatus Chaix ssp. nodulosus (Wahlenb.) H�met-Ahti | northern green rush | Juncaceae
|
| JUAL4 | Juncus alpinoarticulatus Chaix | northern green rush | Juncaceae
|
| JUALN2 | Juncus alpinus Vill. ssp. nodulosus (Wahlenb.) Lindm. | Juncus alpinoarticulatus ssp. nodulosus | Juncaceae
|
| JUALF | Juncus alpinus Vill. var. fuscescens Fern. | Juncus alpinoarticulatus ssp. nodulosus | Juncaceae
|
| JUALR | Juncus alpinus Vill. var. rariflorus Hartman | Juncus alpinoarticulatus ssp. nodulosus | Juncaceae
|
| JUALU | Juncus alpinus Vill. var. uniceps Hartman | Juncus alpinoarticulatus ssp. nodulosus | Juncaceae
|
| JUAL | Juncus alpinus auct. non Vill. | Juncus alpinoarticulatus ssp. nodulosus | Juncaceae
|
| JUAM3 | Juncus ambiguus Guss. | seasice rush | Juncaceae
|
| JUARA | Juncus arcticus Willd. ssp. alaskanus Hult�n | Alaska rush | Juncaceae
|
| JUARA4 | Juncus arcticus Willd. ssp. ater (Rydb.) Hult�n | Juncus balticus var. montanus | Juncaceae
|
| JUARL | Juncus arcticus Willd. ssp. littoralis (Engelm.) Hult�n | Juncus balticus var. littoralis | Juncaceae
|
| JUARA3 | Juncus arcticus Willd. var. alaskanus (Hult�n) Welsh | Juncus arcticus ssp. alaskanus | Juncaceae
|
| JUARL2 | Juncus arcticus Willd. var. littoralis (Engelm.) Boivin | Juncus balticus var. littoralis | Juncaceae
|
| JUARM | Juncus arcticus Willd. var. montanus (Engelm.) Welsh | Juncus balticus var. montanus | Juncaceae
|
| JUARS | Juncus arcticus Willd. var. sitchensis Engelm. | Juncus haenkei | Juncaceae
|
| JUAR2 | Juncus arcticus Willd. | arctic rush | Juncaceae
|
| JUARB3 | Juncus aristulatus Michx. var. biflorus Small | Juncus biflorus | Juncaceae
|
| JUAR7 | Juncus aristulatus auct. non Michx. | Juncus biflorus | Juncaceae
|
| JUAR6 | Juncus arizonicus Wieg. | Juncus interior var. arizonicus | Juncaceae
|
| JUARO | Juncus articulatus L. var. obtusatus Engelm. | Juncus articulatus | Juncaceae
|
| JUAR4 | Juncus articulatus L. | jointleaf rush | Juncaceae
|
| JUAT | Juncus ater Rydb. | Juncus balticus var. montanus | Juncaceae
|