Glebionis segetum
Corn Marigold
Glechoma hederacea
Ground-ivy
Gliricidia sepium
Madre de Cacao
Glyceria declinata
Small Sweet-grass
Glyceria fluitans
Floating Sweet-grass
Glycosmis parviflora
Jamaican Mandarin-orange
Gnaphalium uliginosum
Marsh Cudweed
Goeppertia louisae
Gomphrena celosiodes
Gomphrena Weed
Gomphrena globosa
Globe Amaranth
Gomphrena serrata
Prostrate Globe Amaranth
Guizotia abyssinica
Niger
Gymnadenia borealis
Heath Fragrant-orchid
Gymnadenia conopsea
Fragrant Orchid
Gymnadenia densiflora
Marsh Fragrant-orchid
Hamamelis spp.
Witch-hazel
Hamelia patens
Firebush
Hammarbya paludosa
Bog Orchid
Hedera helix sens lat
Ivy
Hedera hibernica
Atlantic Ivy
Helichrysum arenarium
Helichrysum italicum
Curry-plant
Heliconia monteverdensis
Lobster-claws
Heliconia rostrata
Hanging Lobster Claw
Heliotropium indicum
Indian Heliotrope
Helleborus foetidus
Stinking Hellebore
Helleborus viridis
Green Hellebore
Hellenia speciosa
Crêpe Ginger
Helminthotheca echioides
Bristly Oxtongue
Helosciadium inundatum
Lesser Marshwort
Helosciadium nodiflorum
Fool's-water-cress
Heracleum mantegazzianum
Giant Hogweed
Heracleum sphondylium
Hogweed
Hesperis matronalis
Dame's-violet
Hieracium agg
A Hawkweed
Hieracium angustatiforme
Small-leaved Hawkweed
Hieracium argillaceum
Southern Hawkweed
Hieracium attenboroughianum
Attenborough’s Hawkweed
Hieracium breconense
Brecon Hawkweed
Hieracium clivicola
Hill Hawkweed
Hieracium daedalolepioides
Petite-leaved Hawkweed
Hieracium hypochaeroides
Cat's-ear Hawkweed
Hieracium lanatum
Hieracium repandulare
Hieracium sabaudum
Autumn Hawkweed
Hieracium sanguineum
Bloody Hawkweed
Hieracium sect. Hieracioides
Hieracium sect. Oreadea
Hieracium sect. Sabauda
Hieracium sp.
Hieracium spp
Hieracium subbritannicum
Limestone Hawkweed
Hieracium tavense
Tawe Hawkweed
Himantoglossum hircinum
Lizard Orchid
Hippeastrum puniceum
Amaryllis Lily
Hippobroma longiflora
Star of Bethlehem
Holmskioldia sanguinea
Chinese Hat Plant
Hopea ferrea
Malut
Hordeum distichon
Two-rowed Barley
Hordeum murinum
Wall Barley
Hordeum secalinum
Meadow Barley
Hornungia petraea
Hutchinsia
Humulus lupulus
Hop
Hyacinthoides hispanica
Spanish Bluebell
Hyacinthoides italica
Italian Bluebell
Hyacinthoides non-scripta
Bluebell
Hyacinthoides x massartiana
Garden Bluebell
Hydrangea macrophylla
Hydrangea
Hydrocotyle hirta
Hydrocotyle vulgaris
Marsh Pennywort