Noccaea caerulescens
Alpine Penny-cress
Nonea lutea
Yellow Nonea
Nothofagus alpina
Rauli
Nuphar lutea
Yellow Water-lily
Nymphaea alba
White Water-lily
Nymphaea x marliacea
Coloured Water-lily
Nymphoides peltata
Fringed Water-lily
Ochrolechia parella
Crab-eye Lichen
Ochrolechia tartarea
Odontites vernus
Red Bartsia
Oenanthe aquatica
Fine-leaved Water-dropwort
Oenanthe crocata
Hemlock Water-dropwort
Oenanthe fistulosa
Tubular Water-dropwort
Oenanthe lachenalii
Parsley Water-dropwort
Oenanthe pimpinelloides
Corky-fruited Water-dropwort
Oenanthe silaifolia
Narrow-leaved Water-dropwort
Oenothera biennis
Small-flowered Evening-primrose
Oenothera stricta
Fragrant Evening-primrose
Olearia macrodonta
New Zealand Holly
Omphalina ericetorum
Onobrychis viciifolia
Sainfoin
Ononis repens
Common Restharrow
Ononis spinosa
Spiny Restharrow
Ophioglossum vulgatum
Adder's-tongue
Ophioparma ventosa
Blood-spot Lichen
Ophrys apifera
Bee Orchid
Ophrys fuciflora
Late Spider-orchid
Ophrys insectifera
Fly Orchid
Ophrys insectifera x apifera
Ophrys sphegodes
Early Spider-orchid
Orchis mascula
Early-purple Orchid
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 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
Osmunda regalis
Royal Fern
Oxalis acetosella
Wood-sorrel
Oxalis articulata
Pink-sorrel
Oxalis incarnata
Pale Pink-sorrel
Oxybasis glauca
Oak-leaved Goosefoot
Oxybasis rubra
Red Goosefoot
Panaeolina foenisecii
Brown Mottlegill
Panaeolus papilionaceus
Petticoat Mottlegill
Pancratium maritimum
Sea Daffodil
Papaver cambricum
Welsh Poppy
Papaver dubium
Long-headed Poppy
Papaver lecoqii
Yellow-juiced Poppy
Papaver rhoeas
Common Poppy
Pararge aegeria
Speckled Wood
Parentucellia viscosa
Yellow Bartsia
Parietaria judaica
Pellitory-of-the-wall
Paris quadrifolia
Herb-paris
Parnassia palustris
Grass-of-Parnassus
Pastinaca sativa
Wild Parsnip
Pedicularis palustris
Marsh Lousewort
Pedicularis sylvatica
Lousewort
Pellia endiviifolia
Pellia spp.
Peltigera collina
Dog Lichen