Oregon Cedar (spp.) Oregon Cedar 'Aurea Densa'
Oregon Cedar 'Columnaris' Oregon Cedar 'Erecta'
Oregon Cedar 'Fletcheri' Oregon Cedar 'Globosa Nana'
Oregon Cedar Golden Oregon Cedar Golden
Oregon Cedar 'Green Pillar' Oregon Cedar 'Intertexta'
Oregon Cedar 'Lane' Oregon Cedar 'Lane's Aurea'
Oregon Cedar 'Minima Aurea' Oregon Cedar 'Pembury Blue'
Oregon Cedar 'Pottenii' Oregon Cedar 'Triomf van Boskoop'
Oregon Cedar 'Wisselii' Oregon Cedar 'Yvonne'
Oregon Grape 'Skylark' Oregon Grape (spp.)
Oregon Grape 'Apollo' Oregon Grape 'Compactum'
Oregon Holly Grape (spp.) Oregon Holly Grape 'Apollo'
Oregon Holly Grape 'Compactum' Oregon Holly (spp.)
Oregon Holly 'Apollo' Oregon Holly 'Compactum'
Oregon Lily Oregon Maple
Oregon White Oak Organ Pipe Cactus
Organ Pipe Cactus: thurberi Osage Orange (spp.)
Osage Orange 'Double O' 'Ostbo Red' Mountain Laurel
Ostrich Fern Oswego Tea (spp.)
Oswego Tea 'Jacob Cline' Oswego Tea 'Marshal's Delight'
Oswego Tea 'Panorama' Oswego Tea: Monarda 'Colrain Red'
Oswego Tea: Monarda 'Donnerwolke' Oswego Tea: Monarda 'Petite Wonder'
Oswego Tea: Monarda 'Raspberry Wine' Overcup Oak (spp.)
Ox Eye (spp.) Ox Eye 'Ballerina'
Ox Eye 'Summer Sun' Ox Eye: helianthoides scabra (spp.)
Ox Eye: helianthoides scabra 'Gold Greenheart' Oxalis: stricta
Oxhorn Bucida (spp.) Oxhorn Bucida 'Shady Lady'
Oyster Plant: spathacea (spp.) Oysterwood
Ozark Coneflower Ozark (spp.)
Ozark Sundrops (spp.) Ozark Sundrops 'Silver Wings'
Ozark 'Autumn Embers' Ozark 'Carnea'
Ozark 'Sandra' Pachysandra, Alleghany
Pacific Bleeding Heart 'Bacchanal' Pacific Dogwood
Pacific Madrone Pacific Ninebark
Pacific Onion Pacific Silver Fir
'Pacific Sunset' Flannel Bush Pagoda Dogwood (spp.)
Pagoda Dogwood 'Argentea' Pagoda Lily
Pagoda Tree Paint Leaf (spp.)
Paint Leaf 'Yokoi's White' Paintbrush, Indian (spp.)
Paintbrush, Indian 'Gay Butterflies' Paintbrush, Indian 'Hello Yellow'
Painted Lady Painted Leaf (spp.)
Painted Leaf 'Peterstar Silver Bells' Painted Leaf 'V-14 Pink'
Painted Leaf 'V-17 Angelika White' Painted Leaf 'Winter Rose'
Pajaro Manzanita 'Palace Purple' Alumroot: micrantha
Pale Coneflower Pale Lidflower