New Zealand Purple Flax
Night-blooming Hesperaloe
Noell's Grevillea
Nuevo Leon Rosewood or Narrowleaf R
Ocahui
Ocotillo
Octopus Agave
Ogon Japanese Sweet Flag
Old Man Cactus
Oleander
Oleander Mrs. Roeding
Oleander Sister Agnes
Olive Fruitless Swan Hill
Orchid or Purple Rockrose
Oregon Grape
Oriental arborvitae
Oriental Poppy
Otto Quast Spanish Lavender
Our Lord's Candle
Owl's Clover