Hydrangea petiolaris
Climbing Hydrangea
Hydrangea quercifolia
Oak-leaved Hydrangea
Hydrangea sp
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
Hyoscyamus niger
Henbane
Hypericum
Hypericum androsaemum
Tutsan
Hypericum calycinum
Rose-of-Sharon
Hypericum elodes
Marsh St John's-wort
Hypericum forrestii
Forrest's Tutsan
Hypericum hircinum
Stinking Tutsan
Hypericum hirsutum
Hairy St John's-wort
Hypericum humifusum
Trailing St John's-wort
Hypericum maculatum
Imperforate St John's-wort
Hypericum montanum
Pale St John's-wort
Hypericum perforatum
Perforate St John's-wort
Hypericum pulchrum
Slender St John's-wort