| Abbreviation | Definition |
|---|---|
| ISH | in situ hybridization |
| ISIS | International Species Information System |
| IS-MPMI | International Society for Molecular Plant-Microbe Interactions |
| ITEC | Institute for Tropical Ecology and Conservation |
| J | Jungle |
| J | Juniper |
| J.ENOL.VITIC. | American Journal of Enology and Viticulture |
| JBN | Jardín Botánico Nacional |
| JBRJ | Jardim Botânico do Rio de Janeiro |
| JCRA | J. C. Baulston Arboretum |
| JnK | C-Jun Kinase enzyme |
| JSPT | Japan Society of Plant Taxonomists |
| KB | Killer Bud |
| KGB | Killer Green Bud |
| KO | Killer Offspring |
| L | Lycopodium |
| LACV | Lonomia Achelous Caterpillar Venom |
| LB | Liimii Bug |
| LBG | Lees Botanical Gardens |
| LC | Leaf Color |