Orbea umbracula Oreocereus celsianus
Origanum x 'Kents Beauty' Origanum dictamnus
Origanum dictamnus 'Amargcus Dictamnus' Origanum laevigatum 'Herrenhausen'
Origanum laevigatum 'Rosenkuppel' Origanum majorana 'Compactum'
Origanum majorana 'Sicillian' Origanum pulchellum
Origanum rotundifolium Origanum syriacum
Origanum vulgare Origanum vulgare 'Aureum'
Origanum vulgare 'Thumbles' Origanum vulgare 'Variegatum'
Origanum vulgare ssp. hirtum 'Noa' Ornithogalum dubium 'Orange Cream'
Ornithogalum oligophyllum Ornithogalum umbellatum
Orontium aquaticum Orostachys iwarenge
Osmunda cinnamonea Osmunda claytonia
Osmunda regalis Osmunda regalis 'Purpurescens'
Osmunda regalis var. spectabilis Osteospermum 'Brightside'
Osteospermum 'Flower Power Pink' Osteospermum 'Impassion White'
Osteospermum 'Passion Mix' Osteospermum 'Pinwheel Purple'
Osteospermum 'Pinwheel Rose' Osteospermum 'Pinwheel White Eye'
Osteospermum 'Polar Star' Osteospermum 'Seikilrem (Lemon Symphony)'
Osteospermum 'Sparkler' Osteospermum 'Summeretime Pink Charme'
Osteospermum 'Summertime Sweet Blue Sunrise' Osteospermum 'Summertime Sweet White'
Osteospermum 'Tradewinds™ Deep Purple' Osteospermum 'Tradewinds™ Light Purple'
Osteospermum 'Tradewinds™ Pink' Osteospermum ecklonis
Osteospermum ecklonis 'Akope' Osteospermum ecklonis 'Balostlueye (Blue Eyed Beauty)'
Osteospermum fruticosum Osteospermum fruticosum 'Trailing'
Otacanthus caeruleus Otatea acuminata
Othonna capensis Oxalis crassipes
Oxalis oregana Oxalis purpurea
Oxalis purpurea 'Garnet' Oxalis regnellii
Oxalis regnellii 'Atropurpurea' Oxalis spiralis ssp. vulcanicola
Oxalis tetraphylla Oxalis triangularis
Oxalis viops Oxalis vulcanicola 'Burgundy'
Oxalis vulcanicola 'Copper Glow' Oxalis vulcanicola 'Molten Lava™'
Pachycereus hollianus Pachycereus marginatus
Pachycereus pringlei Pachycereus schottii
Pachycereus schottii var. monstrosus Pachypodium lealii ssp. saundersii
Pachyrhizus tuberosus Pachysandra procumbens
Pachysandra terminalis Pachysandra terminalis 'Cutleaf'
Pachysandra terminalis 'Foliis Variegatis' Pachysandra terminalis 'Green Carpet'
Pachysandra terminalis 'Green Sheen' Pachysandra terminalis 'Silver Edge'
Pachystachys lutea Packera aureus