| Halleria lucida | Halleria abyssinica |
| Hamelia patens | Hamelia coccinea, Hamelia erecta, Hamelia grandiflora, Hamelia sphaerocarpa |
| Hibiscus acetosella | Hibiscus eetveldianus |
| Hibiscus aculeatus | Hibiscus scaber |
| Hibiscus aethiopicus var. aethiopicus | Hibiscus ellipticus, Hibiscus aethiopicus var. genuinus, Hibiscus propinquus, Hibiscus ambelacensis, Hibiscus luteiflorus, Hibiscus aethiopicus var. helvolus |
| Hibiscus calyphyllus | Hibiscus calycinus |
| Hibiscus cisplatinus | Hibiscus striatus |
| Hibiscus coccineus | Hibiscus semilobatus, Hibiscus carolinianus, Hibiscus integrifolius, Hibiscus speciosus |
| Hibiscus engleri | Hibiscus cordatus, Hibiscus irritans, Hibiscus microcylicinus, |
| Hibiscus ferrugineus | Hibiscus crassinervius, Hibiscus shirensis, Hibiscus shirensis var. perrierellus |
| Hibiscus lasiocarpus | Hibiscus californicus, Hibiscus moscheutos ssp. lasiocarpos, Hibiscus moscheutos ssp. lasiocarpus, Hibiscus moscheutos var. occidentalis |
| Hibiscus martianus | Hibiscus cardiophyllus |
| Hibiscus micranthus | Hibiscus micranthus var. micranthus, Hibiscus gossypinus |
| Hibiscus splendens | Abelmoschus splendens |
| Hibiscus tiliaceus | Hibiscus elatus |
| Hovea elliptica | Hovea celsii |
| Hovenia dulcis | Hovenia acerba, Hovenia inequalis |
| Huernia hystrix | Stapelia hystrix |