Houttuynia cordata
Fish-plant
Huperzia selago
Fir Clubmoss
Hyacinthoides non-scripta
Bluebell
Hydrangea macrophylla
Hydrangea
Hydrocotyle vulgaris
Marsh Pennywort
Hylotelephium telephium
Orpine
Hymenocallis fragrans
Spider Lily
Hymenophyllum tunbrigense
Tunbridge Filmy-fern
Hyophorbe lagenicaulis
Bottle Palm
Hyoscyamus niger
Henbane
Hypericum humifusum
Trailing St John's-wort
Hypericum x inodorum
Tall Tutsan
Hypopitys monotropa
Yellow Bird's-nest
Hyptis capitata
False Ironwort
Illecebrum verticillatum
Coral-necklace
Impatiens balsamina
Garden Balsam
Impatiens noli-tangere
Touch-me-not Balsam
Impatiens parviflora
Small Balsam
Impatiens walleriana
Busy Lizzie
Imperata cylindrica
Cogon Grass
Indigofera hirsuta
Hairy Indigo
Indigofera suffruticosa
Guatemalan Indigo
Inonotus hispidus
Shaggy Bracket
Inula helenium
Elecampane