Oak: arexene Oak: arkansana
Oak: brantii Oak: candicans
Oak: carolinianus Oak: castaneifolia
Oak: chrysolepis, Live Oak: emoryi, Live
Oak: falcata, Spanish Oak: hemisphaerica, Laurel
Oak: infectoria Oak: infectoria veneris
Oak: ithaburensis, Vallonea Oak: macrocarpa, Burr
Oak: macrocarpa, Mossy Cup Oak: macroroburhybrid
Oak: marilandica, Blackjack Oak: quadrangulata
Oak: rugosa, Netleaf Oak: salicina
Oak: schuetteihybrid Oak: texana, Spanish
Oak: turnerihybrid Oak: velutina, Black
'Oakhurst' Pineapple Lily 'Oakington Blue Eyes' Moss Phlox
'Oakington Jewel' Alumroot: Heuchera 'Oakleaf' Heartleaf Foamflower
Oakleaf Hydrangea (spp.) Oakleaf Hydrangea 'Alice'
Oakleaf Hydrangea 'Allison' Oakleaf Hydrangea 'Brenhill (Gatsby Gal™)'
Oakleaf Hydrangea 'Gatsby Moon™' Oakleaf Hydrangea 'Gatsby Star™'
Oakleaf Hydrangea 'Harmony' Oakleaf Hydrangea 'Semmes Beauty'
Oakleaf Hydrangea 'Snow Queen' Oakleaf Hydrangea 'Snowflake'
Oakleaf Hydrangea 'Syke's Dwarf' Oakleaf Mountain Ash
Oatgrass, Blue (spp.) Oatgrass, Blue 'Sapphire'
Oats, North American Wild Oats, Northern Sea
Oats, River Oats, Sea
Oats, Spanglegrass River Oats, Wild
Obedient Plant (spp.) Obedient Plant 'Miss Manners'
Obedient Plant 'Mordea Beauty' Obedient Plant 'Pink Bouquet'
Obedient Plant 'Red Beauty' Obedient Plant 'Summer Snow'
Obedient Plant Variegated Oblong Fern
'Obovata' Copperleaf 'Obsession Red With Eye' Bedding Verbena
Ocean Spray Ochrosia
Oconee Azalea Oconee Bells
Ocotillo Ocotillo Macho
Ocotillo, Tree Ocotillo: macdougalii
Ocotillo: purpusii Ocotillo: splendens
October Daphne (spp.) October Daphne Dwarf
October Plant (spp.) October Plant Dwarf
Octopus Agave Octopus Plant (spp.)
Octopus Plant Variegated Octopus Plant: actinophylla (spp.)
Octopus Plant: actinophylla 'Amate™' Octopus Tree (spp.)
Octopus Tree 'Amate™' Ogeechee Lime
Ogeechee Tupelo 'Ogi nagare' Japanese Maple
'Ogon' Dwarf Sweet Flag 'Ogon' Makino Stonecrop
Ohio Buckeye (spp.) Ohio Buckeye 'Monticola'
Ohio Buckeye 'Sargentii' Ohio Buckeye: glabra pallida
Ohio Spiderwort 'Mrs. Loewer' 'Ohlendorfii' Norway Spruce
Oil Grass Oil Tree, Poonga
'Oiseau Bleu' Rose of Sharon 'Ojochin' Oriental Cherry
'Okame' Heavenly Bamboo Okame Zasa
'Okima' Japanese Maple