Orchis militaris
Military Orchid
Orchis purpurea
Lady Orchid
Orchis simia
Monkey Orchid
Orchis x angusticruris
Lady#Orchid#/ Monkey#Orchid#hybrid
Oreopteris limbosperma
Lemon-scented Fern
Origanum vulgare
Wild Marjoram
Ornithogalum nutans
Drooping Star-of-Bethlehem
Ornithogalum pyrenaicum
Spiked Star-of-Bethlehem
Ornithogalum umbellatum
Star-of-Bethlehem
Ornithopus perpusillus
Bird's-foot
Orobanche caryophyllacea
Bedstraw Broomrape
Orobanche hederae
Ivy Broomrape
Orobanche minor
Common Broomrape
Orobanche picridis
Oxtongue Broomrape
Orobanche rapum-genistae
Greater Broomrape
Orthilia secunda
Serrated Wintergreen
Osmoxylon lineare
Green Aralia
Osmunda regalis
Royal Fern
Oxalis acetosella
Wood-sorrel
Oxalis articulata
Pink-sorrel
Oxalis corniculata
Creeping Woodsorrel
Oxalis incarnata
Pale Pink-sorrel
Oxalis triangularis
False Shamrock
Oxybasis glauca
Oak-leaved Goosefoot
Oxybasis rubra
Red Goosefoot
Pachira glabra
French Peanut
Paeonia peregrina
Peony
Palhinhaea cernua
Staghorn Clubmoss
Pancratium maritimum
Sea Daffodil
Pandanus tectorius
Thatch Screwpine
Panicum trichanthum
Thicket Panic Grass
Papaver cambricum
Welsh Poppy
Papaver dubium
Long-headed Poppy
Papaver lecoqii
Yellow-juiced Poppy
Papaver rhoeas
Common Poppy
Papaver setiferum
Oriental Poppy
Paphiopedilum callosum
Callus Paphiopedilum
Paphiopedilum hirsutissimum
Paphiopedilum spp.
Ladyslipper
Parentucellia viscosa
Yellow Bartsia
Parietaria judaica
Pellitory-of-the-wall
Paris quadrifolia
Herb-paris
Parnassia palustris
Grass-of-Parnassus
Passiflora caerulea
Blue Passionflower
Passiflora capsularis
Passion#Flower#(capsularis)
Passiflora foetida
Stinking Passionflower
Pastinaca sativa
Wild Parsnip
Paulownia tomentosa
Foxglove-tree
Pedicularis foliosa
Leafy Lousewort
Pedicularis palustris
Marsh Lousewort
Pedicularis sylvatica
Lousewort
Pelargonium zonale
Zonal Geranium
Pellia endiviifolia
Pellia spp.
Penstemon sp.
Penstemon
Pentaglottis sempervirens
Green Alkanet
Pentas lanceolata
Egyptian Starcluster
Peperomia pellucida
Pepper Elder
Peperomia polybotrya
Raindrop Peperomia
Pereskia aculeata
Barbados Gooseberry
Persicaria amphibia
Amphibious Bistort
Persicaria chinensis
Creeping Smartweed
Persicaria hydropiper
Water-pepper
Persicaria lapathifolia
Pale Persicaria
Persicaria maculosa
Redshank
Persicaria minor
Small Water-pepper
Persicaria mitis
Tasteless Water-pepper
Petasites hybridus
Butterbur
Petasites japonicus
Giant Butterbur
Petasites pyrenaicus
Winter Heliotrope