Humulus lupulus
Hop
Hydrocotyle vulgaris
Marsh Pennywort
Hypericum androsaemum
Tutsan
Hypericum hircinum
Stinking Tutsan
Hypericum humifusum
Trailing St John's-wort
Hypopitys monotropa
Yellow Bird's-nest
Hyptis capitata
False Ironwort
Iberis amara
Wild Candytuft
Iberis umbellata
Garden Candytuft
Ilex aquifolium
Holly
Impatiens glandulifera
Indian Balsam
Iris foetidissima
Stinking Iris
Isatis tinctoria
Woad
Isolepis setacea
Bristle Club-rush
Jatropha gossypiifolia
Bellyache Bush
Juglans regia
Walnut
Juncus acutus
Sharp Rush
Juncus articulatus
Jointed Rush
Juncus bulbosus
Bulbous Rush
Juncus compressus
Round-fruited Rush
Juncus inflexus
Hard Rush
Juncus tenuis
Slender Rush
Juniperus communis
Juniper
Laburnum anagyroides
Laburnum