| Common name (English) | |
|---|---|
| Ginkgo biloba | Maidenhair-tree |
| Glandularia aristigera | Fine-Leafed Verbena |
| Gleditsia triacanthos | Honey locust |
| Gossypium herbaceum | Arabian cotton |
| Gossypium hirsutum | American cotton |
| Grevillea robusta | Australian Silky Oak |
| Guizotia abyssinica | niger-seed |
| Hesperocyparis arizonica | Arizona cypress, Stanta Cruz cypress |
| Hesperocyparis lusitanica | Mexican cedar |
| Hesperocyparis macrocarpa | Monterey cypress |
| Hibiscus rosa-sinensis | China rose, Shoe flower, Chinese hibiscus |
| Hibiscus syriacus | Rose of Sharon |
| Howea belmoreana | Belmore palm |
| Humulus scandens | Japanese Hop |
| Ilex aquifolium | English holly |
| Iresine diffusa f. herbstii | Bloodleaf |
| Iris xiphium | Spanish Iris |
| Jacaranda mimosifolia | Black poui, Blue Brazilian |
| Jacobaea maritima subsp. maritima | |
| Jasminum angulare | wild jasmine; angular jasmine |