Hypericum montanum
Pale St John's-wort
Hypericum perforatum
Perforate St John's-wort
Hypericum pulchrum
Slender St John's-wort
Hypericum tetrapterum
Square-stalked St John's-wort
Hypericum x caesariense
Hypericum x desetangsii
Des Etangs' St John's-wort
Hypericum x inodorum
Tall Tutsan
Hypnum cupressiforme
Hypochaeris maculata
Spotted Cat's-ear
Hypochaeris radicata
Cat's-ear
Hypopitys monotropa
Yellow Bird's-nest
Hyptis capitata
False Ironwort
Iberis amara
Wild Candytuft
Iberis umbellata
Garden Candytuft
Ilex aquifolium
Holly
Illecebrum verticillatum
Coral-necklace
Impatiens glandulifera
Indian Balsam
Impatiens noli-tangere
Touch-me-not Balsam
Impatiens parviflora
Small Balsam
Impatiens walleriana
Busy Lizzie
Imperata
Inula conyzae
Ploughman's-spikenard
Inula helenium
Elecampane
Ipomoea aquatica
Water Spinach