Hordeum murinum
Wall Barley
Hornungia petraea
Hutchinsia
Houttuynia cordata
Fish-plant
Humulus lupulus
Hop
Huperzia selago
Fir Clubmoss
Hyacinthoides hispanica
Spanish Bluebell
Hyacinthoides italica
Italian Bluebell
Hyacinthoides non-scripta
Bluebell
Hydrangea petiolaris
Climbing Hydrangea
Hydrocharis morsus-ranae
Frogbit
Hydrocotyle hirta
Hydrocotyle vulgaris
Marsh Pennywort
Hylotelephium telephium
Orpine
Hymenocallis fragrans
Spider Lily
Hymenophyllum tunbrigense
Tunbridge Filmy-fern
Hymenophyllum wilsonii
Wilson's Filmy-fern
Hyophorbe lagenicaulis
Bottle Palm
Hypericum androsaemum
Tutsan
Hypericum elodes
Marsh St John's-wort
Hypericum hirsutum
Hairy St John's-wort
Hypericum humifusum
Trailing St John's-wort
Hypericum maculatum
Hypericum montanum
Pale St John's-wort
Hypericum perforatum
Perforate St John's-wort