Myosotis alpestris
Alpine Forget-me-not
Myosotis arvensis
Field Forget-me-not
Myosotis discolor
Changing Forget-me-not
Myosotis laxa
Tufted Forget-me-not
Myosotis ramosissima
Early Forget-me-not
Myosotis scorpioides
Water Forget-me-not
Myosotis secunda
Creeping Forget-me-not
Myosotis stricta
Myosotis sylvatica
Wood Forget-me-not
Myosurus minimus
Mousetail
Myrica gale
Bog-myrtle
Myriophyllum alterniflorum
Alternate Water-milfoil
Myriophyllum aquaticum
Parrot's-feather
Myriophyllum spicatum
Spiked Water-milfoil
Myrrhis odorata
Sweet Cicely
Nasturtium officinale
Water-cress
Nepenthes spp.
Pitcherplant
Nepenthes truncata
Nepeta x faassenii
Garden Cat-mint
Nerium oleander
Oleander
Neustanthus phaseoloides
Tropical Kudzu
Nicandra physalodes
Apple-of-Peru
Noccaea caerulescens
Alpine Penny-cress
Nonea lutea
Yellow Nonea
Nothofagus alpina
Rauli
Nymphoides peltata
Fringed Water-lily
Ochna serrulata
Small-leaved Plane
Ocimum americanum
American Basil
Ocinum americanum
American Basil
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 glazioviana
Large-flowered Evening-primrose
Oenothera stricta
Fragrant Evening-primrose
Olearia macrodonta
New Zealand Holly
Onobrychis viciifolia
Sainfoin
Ononis arvensis
Ononis reclinata
Small Restharrow
Ononis repens
Common Restharrow
Ononis spinosa
Spiny Restharrow
Opuntia cochenillifera
Cochineal Cactus
Opuntia ficus-indica
Prickly Pear
Opuntia microdasys
Angel's-wings
Origanum vulgare
Wild Marjoram
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
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
Papaver cambricum
Welsh Poppy
Papaver dubium
Long-headed Poppy
Papaver lecoqii
Yellow-juiced Poppy
Papaver rhoeas
Common Poppy