Heracleum mantegazzianum
Giant Hogweed
Hesperis matronalis
Dame's-violet
Hirschfeldia incana
Hoary Mustard
Hyacinthoides hispanica
Spanish Bluebell
Hyacinthoides italica
Italian Bluebell
Hyacinthoides x massartiana
Garden Bluebell
Hydrangea macrophylla
Hydrangea
Hypericum calycinum
Rose-of-Sharon
Hypericum forrestii
Forrest's Tutsan
Hypericum hircinum
Stinking Tutsan
Hypericum x inodorum
Tall Tutsan
Impatiens glandulifera
Indian Balsam
Impatiens parviflora
Small Balsam
Iris foetidissima
Stinking Iris
Iris sibirica
Siberian Iris
Iris unguicularis
Algerian Iris
Jasminum nudiflorum
Winter Jasmine
Juglans regia
Walnut
Juncus tenuis
Slender Rush
Laburnum anagyroides
Laburnum
Laburnum x watereri
Hybrid Laburnum
Lagarosiphon major
Curly Waterweed
Lagurus ovatus
Hare's-tail
Lamium maculatum
Spotted Dead-nettle