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
Ipomoea aquatica
Water Spinach
Ipomoea batatas
Sweet Potato
Ipomoea carnea
Pink Morning Glory
Ipomoea hederacea
Ivy-leaved Morning Glory
Ipomoea obscura
Obscure Morning Glory
Ipomoea tricolor
Mexican Morning Glory
Ipomoea triloba
Aiea Morning Glory
Isoetes lacustris
Quillwort
Ixora chinensis
Chinese Ixora
Jaapiella veronicae