Helleborus foetidus
Stinking Hellebore
Helleborus viridis
Green Hellebore
Helminthotheca echioides
Bristly Oxtongue
Helosciadium inundatum
Lesser Marshwort
Helosciadium nodiflorum
Fool's-water-cress
Heracleum mantegazzianum
Giant Hogweed
Heracleum sphondylium
Hogweed
Hesperis matronalis
Dame's-violet
Hieracium anglicum agg.
Hawkweed (anglicum agg.)
Hieracium cillense
Craig y Cilau Hawkweed
Hieracium lanatum
Hieracium maculatum
Spotted Hawkweed
Hieracium repandulare
Repand-leaved Hawkweed
Hieracium sect. Sabauda
Hieracium sect. Stelligera
Hawkweed (Stelligera)
Hieracium sect. Vulgata
Hieracium subbritannicum
Hippuris vulgaris
Mare's-tail
Hornungia petraea
Hutchinsia
Hottonia palustris
Water-violet
Houttuynia cordata
Fish-plant
Humulus lupulus
Hop
Huperzia selago
Fir Clubmoss
Hyacinthoides italica
Italian Bluebell