Heracleum mantegazzianum
Giant Hogweed
Heracleum sphondylium
Hogweed
Hesperis matronalis
Dame's-violet
Hieracium agg
A Hawkweed
Hieracium angustatiforme
Small-leaved Hawkweed
Hieracium apheles
Hepste Hawkweed
Hieracium argillaceum
Southern Hawkweed
Hieracium attenboroughianum
Attenborough’s Hawkweed
Hieracium breconense
Brecon Hawkweed
Hieracium breconicola
Beacon's Hawkweed
Hieracium cillense
Craig y Cilau Hawkweed
Hieracium clivicola
Hill Hawkweed
Hieracium daedalolepioides
Petite-leaved Hawkweed
Hieracium discophyllum
Disc-leaved Hawkweed
Hieracium hypochaeroides
Cat's-ear Hawkweed
Hieracium inspissatum
Crass-leaved Hawkweed
Hieracium leyanum
Fat-leaved Hawkweed
Hieracium neocoracinum
Craig Gleisiad Hawkweed
Hieracium repandulare
Hieracium reticulatiforme
Reticulate-leaved Hawkweed
Hieracium sabaudum
Autumn Hawkweed
Hieracium sanguineum
Bloody Hawkweed
Hieracium sect. Hieracioides
Hieracium sect. Oreadea
Hieracium sect. Sabauda
Hieracium sp.
Hieracium spp
Hieracium stenopholidium
Western Hawkweed
Hieracium subbritannicum
Limestone Hawkweed
Hieracium tavense
Tawe Hawkweed
Hippuris vulgaris
Mare's-tail
Hirudo medicinalis
Hordeum secalinum
Meadow Barley
Hornungia petraea
Hutchinsia
Huperzia selago
Fir Clubmoss
Hyacinthoides hispanica
Spanish Bluebell
Hyacinthoides non-scripta
Bluebell
Hyacinthoides x massartiana
Garden Bluebell
Hydrocotyle vulgaris
Marsh Pennywort
Hygrocybe calyptriformis
Pink Waxcap
Hygrocybe coccinea
Scarlet waxcap
Hygrocybe conica
Blackening Wax Cap
Hygrocybe miniata
Hygrocybe psittacina
Parrot Waxcap
Hygrocybe sp.
Hygrocybe virginea
Snowy Waxcap
Hylotelephium telephium
Orpine
Hymenophyllum tunbrigense
Tunbridge Filmy-fern
Hymenophyllum wilsonii
Wilson's Filmy-fern
Hypericum androsaemum
Tutsan
Hypericum elodes
Marsh St John's-wort
Hypericum hirsutum
Hairy St John's-wort
Hypericum humifusum
Trailing St John's-wort
Hypericum maculatum
Hypericum pulchrum
Slender St John's-wort
Hypericum x inodorum
Tall Tutsan
Hypholoma fasciculare
Sulphur Tuft
Hypnum cupressiforme
Hypochaeris radicata
Cat's-ear
Hypogymnia tubulosa
Hypopitys monotropa
Yellow Bird's-nest
Ilex aquifolium
Holly
Impatiens glandulifera
Indian Balsam
Inonotus dryadeus
Oak Bracket
Iris foetidissima
Stinking Iris
Iris pseudacorus
Yellow Iris
Isoetes lacustris
Quillwort
Isolepis setacea
Bristle Club-rush
Jacobaea aquatica
Marsh Ragwort
Jasione montana
Sheep's-bit