- genus hamelia
- genus haminoea
- genus haplopappus
- genus hardenbergia
- genus harpia
- genus harpullia
- genus harrisia
- genus hatiora
- genus hazardia
- genus hedeoma
- genus hedera
- genus hedysarum
- genus helenium
- genus heleodytes
- genus heliamphora
- genus helianthemum
- genus helianthus
- genus helichrysum
- genus helicteres
- genus heliobacter
- genus heliophila
- genus heliopsis
- genus heliothis
- genus helipterum
- genus helix
- genus helleborus
- genus helminthostachys
- genus heloderma
- genus helotium
- genus helvella
- genus helwingia
- genus helxine
- genus hemachatus
- genus hemerocallis
- genus hemigalus
- genus hemigrammus
- genus hemipteronatus
- genus hemitripterus
- genus hepatica
- genus heracleum
- genus heritiera
- genus hermannia
- genus hermissenda
- genus hernaria
- genus herpestes
- genus herrerasaurus
- genus hesperiphona
- genus hesperis
- genus heteranthera
- genus heterocephalus
- genus heterodon
- genus heteromeles
- genus heteroscelus
- genus heterotheca
- genus heuchera
- genus hevea
- genus hexagrammos
- genus hexalectris
- genus hexamita
- genus hexanchus
- genus hibbertia
- genus hibiscus
- genus hieracium
- genus himantoglossum
- genus himantopus
- genus hippeastrum
- genus hippobosca
- genus hippocampus
- genus hippocrepis
- genus hippodamia
- genus hippoglossoides
- genus hippoglossus
- genus hippopotamus
- genus hipposideros
- genus hippotragus
- genus hipsurus
- genus hirudo
- genus hirundo
- genus hoheria
- genus holarrhena
- genus holbrookia
- genus holcus
- genus holocentrus
- genus holothuria
- genus homarus
- genus homo
- genus homogyne
- genus homona
- genus hordeum
- genus horneophyton
- genus hosta
- genus hottonia
- genus houttuynia
- genus hovea
- genus hoya
- genus hudsonia
- genus hugueninia
- genus hulsea
- genus humulus
- genus hunnemania
- genus hyacinthoides
- genus hyacinthus
- genus hyaena
- genus hyalophora
- genus hyalosperma
- genus hybanthus
- genus hydnocarpus
- genus hydnum
- genus hydra
- genus hydrangea
- genus hydrastis
- genus hydrilla
- genus hydrobates
- genus hydrocharis
- genus hydrochoerus
- genus hydrodamalis
- genus hydromantes
- genus hydromys
- genus hydrophyllum
- genus hyemoschus
- genus hygrocybe
- genus hygrophorus
- genus hygrotrama
- genus hyla
- genus hylactophryne
- genus hylobates
- genus hylocereus
- genus hylocichla
- genus hylophylax
- genus hymenaea
- genus hymenanthera
- genus hymenophyllum
- genus hynerpeton
- genus hyoscyamus
- genus hypentelium
- genus hypericum
- genus hyperoglyphe
- genus hyperoodon
- genus hyphantria
- genus hypochaeris
- genus hypochoeris
- genus hypoderma
- genus hypopachus
- genus hypopitys
- genus hypoxis
- genus hypsiglena
- genus hypsiprymnodon
- genus hyracotherium
- genus hyssopus
- genus iberis
- genus ibero-mesornis
- genus ibis
- genus ichthyosaurus
- genus ichthyostega
- genus ictalurus
- genus icteria
- genus icterus
- genus ictiobus
- genus ictonyx
- genus idesia
- genus iguana
- genus iguanodon
- genus ilex
- genus iliamna
- genus illecebrum
- genus illicium
- genus impatiens
- genus inachis
- genus indigofera
- genus indri
- genus inga
- genus inula
- genus ipomoea
- genus irena
- genus iresine
- genus iridoprocne
- genus iris
- genus irvingia
- genus isatis
- genus ischigualastia
- genus isoetes
- genus isopyrum
- genus istiophorus
- genus isurus
- genus iva
- genus ixia
- genus ixobrychus
- genus ixodes
- genus jabiru
- genus jacksonia
- genus jacquinia
- genus jaculus
- genus jambos
- genus jamesonia
- genus jasminum
- genus jatropha
- genus javanthropus
- genus jordanella
- genus juglans
- genus junco