This list includes 25 Flowers that start with O, from “Obedient Plant” to “Ozark Witch Hazel”. They range from garden favorites to wild woodland species, useful for borders, bouquets and pollinator beds.
Flowers that start with O are a varied group of showy plants used in gardens, bouquets and natural habitats. Notable examples include the Obedient Plant, a resilient perennial often used in North American prairie restorations.
Below you’ll find the table with scientific name, colors, locations and season.
Scientific name: Binomial names show genus and species so you can confirm exact identity and compare similar plants.
Colors: Primary flower colors help you choose plants for design, season contrast and matching bouquets or garden schemes.
Locations: Native and naturalized regions indicate where each species thrives and where you might expect to find them.
Season: Typical flowering months or seasons show when blooms appear, helping you plan planting and cutting schedules.
Flowers that start with O
| Name | Scientific name | Colors | Locations & season |
|---|---|---|---|
| Oleander | Nerium oleander | Pink, white, red | Mediterranean; Summer (N. Hemisphere) |
| Opium Poppy | Papaver somniferum | White, pink, purple | Mediterranean; Early summer (N. Hemisphere) |
| Orchid | Orchidaceae family | All colors | Worldwide, except Antarctica; Varies by species |
| Orchid Cactus | Disocactus ackermannii & hybrids | Red, pink, white | Mexico (native); Spring to early summer |
| Orchid Tree | Bauhinia variegata | Pink, purple, white | Southeast Asia; Late winter to spring |
| Oregano | Origanum vulgare | Pink, purple, white | Mediterranean; Summer (N. Hemisphere) |
| Oregon Grape | Mahonia aquifolium | Yellow | Western North America; Spring |
| Oregon Sunshine | Eriophyllum lanatum | Yellow | Western North America; Late spring to summer |
| Oriental Poppy | Papaver orientale | Orange, red, pink | Southwest Asia; Late spring to early summer |
| Orlaya | Orlaya grandiflora | White | Mediterranean; Summer (N. Hemisphere) |
| Orpine | Hylotelephium telephium | Pink, red, white | Eurasia; Late summer to fall |
| Osmanthus | Osmanthus fragrans | White, cream, orange | Asia; Fall, winter, or spring |
| Osteospermum | Osteospermum spp. | Purple, white, yellow | Southern Africa; Spring to fall |
| Owl’s Clover | Castilleja exserta | Pink, magenta, purple | Western North America; Spring |
| Ox-eye Daisy | Leucanthemum vulgare | White | Europe, Asia; Late spring to summer |
| Oxalis | Oxalis spp. | Pink, white, yellow | Worldwide; Varies by species, often spring to fall |
| Obedient Plant | Physostegia virginiana | Pink, white | Eastern North America; Late summer to fall |
| Oconee Bells | Shortia galacifolia | White, pink | Southeastern United States; Early spring |
| Ocean Spray | Holodiscus discolor | White, cream | Western North America; Early to mid-summer |
| Ohio Spiderwort | Tradescantia ohiensis | Blue, purple, pink | Eastern & Central North America; Late spring to mid-summer |
| Orange Blossom | Citrus sinensis | White | Southeast Asia (cultivated worldwide); Spring |
| Orange Daylily | Hemerocallis fulva | Orange | Asia (naturalized worldwide); Summer |
| Orange Star | Ornithogalum dubium | Orange, yellow | South Africa; Late winter to spring |
| Ozark Phlox | Phlox pilosa subsp. ozarkana | Pink, purple, lavender | Central United States (Ozarks); Spring |
| Ozark Witch Hazel | Hamamelis vernalis | Yellow, red | Central United States (Ozarks); Winter |
Descriptions
Oleander
A popular, drought-tolerant evergreen shrub known for its beautiful flowers. All parts are highly poisonous.
Opium Poppy
Famous annual known as the source of opium and edible poppy seeds for baking.
Orchid
One of the largest plant families, with over 28,000 species known for their complex flowers.
Orchid Cactus
A jungle cactus with stunning, large, orchid-like flowers and flat, leaflike stems. Often grown in baskets.
Orchid Tree
A tropical tree prized for its large, fragrant flowers that resemble showy orchids.
Oregano
A popular culinary herb with small but numerous flowers that are highly attractive to bees and pollinators.
Oregon Grape
An evergreen shrub with holly-like leaves and bright yellow flower clusters. It is the state flower of Oregon.
Oregon Sunshine
A perennial wildflower with woolly, silver-gray foliage and cheerful, daisy-like yellow flowers. Thrives in sun.
Oriental Poppy
A perennial with huge, papery, crepe-like flowers and bold black centers. Goes dormant in the heat of summer.
Orlaya
A delicate annual with flat-topped clusters of pure white flowers that look like fine Queen Anne’s lace.
Orpine
A hardy succulent perennial, also known as live-forever, with fleshy leaves and dense flower heads attractive to butterflies.
Osmanthus
An evergreen shrub or small tree famed for its tiny but intensely fragrant, apricot-scented flowers.
Osteospermum
Often called African Daisy, these cheerful tender perennials thrive in sun and cool weather, closing at night.
Owl’s Clover
A vibrant wildflower with dense, spiky flower heads that resemble a colorful owl’s feather tuft.
Ox-eye Daisy
A classic wildflower with white-rayed, yellow-centered flowers, commonly seen in meadows, pastures, and roadsides.
Oxalis
A large genus of plants, also known as wood sorrels, with distinctive clover-like leaves and delicate flowers.
Obedient Plant
Named for its unique flowers on square stems that can be bent into a new position and will stay there briefly.
Oconee Bells
A rare, low-growing woodland perennial with shiny evergreen leaves and delicate, bell-shaped nodding flowers.
Ocean Spray
A deciduous shrub that produces dramatic, arching sprays of tiny, creamy-white flowers, resembling sea foam.
Ohio Spiderwort
A prairie wildflower with three-petaled flowers that famously open in the morning and close by afternoon.
Orange Blossom
The incredibly fragrant flower of the orange tree, a symbol of good fortune and widely used in perfumes.
Orange Daylily
A hardy, prolific perennial also called the ditch lily. Its individual trumpet-shaped flowers last only for one day.
Orange Star
A bulbous plant that produces vibrant, long-lasting, star-shaped flowers in dense clusters. Popular as a pot plant.
Ozark Phlox
A beautiful subspecies of downy phlox native to the Ozark Mountains, with fragrant, star-shaped flowers.
Ozark Witch Hazel
A shrub that provides rare winter interest with its spidery, fragrant flowers that bloom on bare branches.
