Since time immemorial, flowers have been admired across human societies. Looking at flowers gives pleasure to most humans. Some varieties of flowers have found a place in gardens and some spread cheer blooming in the wild. With so many flowers to discover, here is a list of flowers that start with O.



Scientific name: Orchidaceae

Origin: Asia, Australia

The orchid family is truly large with about thirty thousand species thriving worldwide and still growing. Orchids are ancient flowering plants known to have existed for almost twenty million years.

Undoubtedly, orchids are one of the most pretty flowers that start with O. The exotic-looking, beautiful fragrant flowers, with dramatic shapes, and vibrant colors were called ‘Orchis’ by the Greeks in ancient times. The meaning of orchis was testicles, owing to the shape of the flowers. Later, the genus name was changed to Orchidaceae.

Orchids need care and a proper environment to bloom. They are often grown in greenhouses and glasshouses for their unique flowers. For their delicate nature and mesmerizing beauty, orchids symbolize beauty, love, purity, innocence, refinement, and luxury. In different cultures, orchids represent different things.

Some varieties of orchids are –

  • Moth orchid
  • Vanda
  • Boat orchid
  • Butterfly orchid
  • Tiger orchid
  • Slipper orchid
  • Miltonia
  • Dancing lady orchid
  • Maxillaria
  • Tulip orchid
  • Pleione

Orchids are found in all possible colors, the blue variety being the rarest. They bloom in shades of red, purple, pink, yellow, orange, white, and even bicolor. Orchids thrive well in moist, well-drained soil. They like sunlight that’s not too strong. These plants mostly grow in wet tropical hills and forests and can be either epiphytic or terrestrial. That means the plants can grow either hanging in the air or rooted in the soil. Most of the wild orchid species cling to larger plants.


2.Oriental Poppy

Scientific name: Papaver orientale

Origin: Asia

Looking like crepe paper flowers, Oriental poppies are herbaceous perennial flowering plants native to Turkey, and northern Iran. The plants have hairy leaves and thin stems. Most commonly found in orange, and bright red, large, delicate flowers bloom as a single flowerhead from each extremely slender stem. Flowers can also be seen in near-neon colors as well as gorgeous pastels. These showy plants are mostly grown for their fascinatingly colorful flowers. Often used as landscaping flowers, poppies also have medicinal use.

Some varieties of oriental poppies are –

  • Papaver orientale ‘Maiden’s Blush’
  • Papaver orientale ‘Beauty of Livermere’
  • Papaver orientale ‘Patty’s Plum’
  • Papaver orientale ‘Turkenlouis’
  • Papaver orientale ‘Garden Glory’
  • Papaver orientale ‘Avebury Crimson’
  • Papaver orientale ‘Wisley Beacon’
  • Papaver orientale ‘Manhattan’
  • Papaver orientale ‘Bolero’
  • Papaver orientale ‘Fireball’
  • Papaver orientale ‘Princess Victoria Louise’

Oriental poppies grow well in well-drained, compost-rich soil. Full sun promotes flowering. Cold-tolerant oriental poppies cannot bear extreme heat and bloom from spring to early summer. Oriental poppies are good cut flowers when cut early in the morning and placed in water. Oriental poppies are one of the brightest flowers that start with O.



Scientific name: Nerium oleander

Origin: Mediterranean region, North Africa

Oleander, a species of evergreen shrubs from the genus Nerium, belongs to the dogbane family, Apocynaceae. Not only do these plants have a poisonous milky juice, any part of oleander if eaten can cause severe poisoning in humans and animals. Oleander plants grow vigorously in warm climates and produce rose-like flowers.

Common oleander is the most popular variety of oleander and is often called rosebay. The shrubby plants have green lance-shaped leaves growing on fleshy stems. The flowers bloom clusters mostly in light pink. White and yellow oleander varieties are rare. The flowers have a sweet vanilla-like fragrance. Oleanders are hardy plants that are mostly grown outdoors for their ornamental flowers. These are often planted as windbreakers and hedge plants. Oleander flowers symbolize romance, desire, endurance, destiny, and power.


4.Oriental Lily

Scientific name: Orchidaceae

Origin: Japan

A member of the lily family, Oriental lilies belong to the genus Lilium Like other lilies, these bulbous plants also grow from bulbs and bear large, showy, flowers. Oriental lily flowers have a strong fragrance. The slow-growing plants can grow up to a height of four feet. Oriental lilies bloom from mid-summer to the end of summer.

Oriental lily flowers have six petals that are either single-colored or rimmed with a darker or lighter shade or another color. Trumpet-shaped oriental lilies have six petals. The flowers bloom on top of tall erect stems. They bloom in shades of red, orange, yellow, pink, and white. Oriental lilies are associated with rebirth, innocence, sweetness, and purity of heart. They often find a place in wedding bouquets and congratulatory bouquets. Oriental lilies are one of the most popular blooms among the flowers that start with O.



Scientific name: Osteospermum

Origin: Africa

Commonly known as African daisies or daisybushes, Osteospermums are sun-loving plants that belong to the family Calenduleae. The plants originally from Africa grow well in well-drained soil and can also tolerate dry soils. The annual flowering plants start blooming from mid-summer. The daisy-like flowers blooming in an array of bright colors have become popular garden flowers in recent times. These flowers have a blue-purple center and white, peach, apricot, or mostly lavender or purple petals.

Some varieties of Osteospermums are –

  • ‘Serenity Lavender Frost’ Osteospermum
  • Osteospermum ‘Serenity Purple’
  • ‘Peach Symphony’ Osteospermum
  • ‘Mara’ Osteospermum
  • ‘Flower Power Spider White’ Osteospermum


6.Ocean Pearls

Scientific name: Agrostemma githago

Origin: Europe

Also known as white corn cockles, Ocean pearl flowers have milky white petals with dots or specks at the center looking like hand-drawn lines. Some of the varieties also feature small purple flowers. Blooming in early summer, Ocean pearl flowers make excellent garden flowers as they delicately sway even in the slightest breeze. In the wild, they are abundantly found in meadows, rye and wheat fields in Europe. The flowers bloom on slender stems and are considered a typical cottage garden flower. They are easy to grow in well-drained soil and full sun. These pretty white blooms make excellent cut flowers.


7.Obedient Plant Flower

Scientific name: Physostegia virginiana

Origin: North America

Known by other names like obedience, and false dragonhead, obedient plants are a member of the flowering mint family, Lamiaceae. The American wildflower species bears beautiful flowers on long spikes. The plants get their name from the well-arranged flowers on the stalk and their ability to stay in place when twisted.

Obedient plants flower in late summer and early fall. The flowers feature spires of pink snapdragon-like blooms. The plants bloom in full sun, well-drained moist soil. They can also be grown in pots.


8.Ornamental Onion

Scientific name: Allium giganteum

Origin: Asia

Ornamental onions are bulbous perennials that belong to the genus allium, the same as onions. Ornamental onions have attractive flowers in large, globular, or ball-like arrangements. However, apart from their pom-pom-like shape, they may also form pendulous, semi-circular, star, or cup-shaped flowers.

The flowers are white, yellow, blue, mauve, and lilac. The flowers bloom on spongy, hollow stalks in late spring or early summer. Ornamental onion plants bloom in full sun and grow in well-drained soil like other onion species.



Scientific name: Orlaya grandiflora

Origin: Europe

Also known as white lace flowers, Orlaya flowering plants belong to the family, Apiaceae. There are about eleven species of orlaya plants. These hardy annual flowering plants have finely-divided leaves, and lacy pink or white flowers. They are widely cultivated as ornamental flowers. Orlaya flowers bloom in large, flat, bunches, in early summer and continue to flower till early winter.

Orlaya plants need little care and are often grown in cottage gardens, flower beds, and borders.


10.Orange Blossom

Botanical name: Citrus sinensis

Origin: Asia

Orange blossom is the flower of the well-loved citrus orange fruit belonging to the Rutaceae family. White orange blossoms are not only beautiful and fragrant but are also used in a variety of things. They are used for making perfume and teas. These flowers are also considered an aphrodisiac. Orange blossoms are connected to good fortune. In biblical times, wreaths of orange blossoms were worn during weddings. The fragrant flowers bloom from summer to early fall. Orange blossoms are not one of the pretty cut flowers that start with O but are admired greatly for their sweet smell.



Scientific name: Ornithogalum sp.

Origin: Eurasia and Africa

Commonly known as Star of Bethlehem, and Arabian starflower, Ornithogalum flowers are six-petaled, white, delicate, starry flowers. Ornithogalum plants belong to the family Asparagaceae. They are bulbous herbs with narrow or strap-like leaves. The flowers bloom on leafless, slender stalks. The plants grow in partial shade, and well-drained soil, and make excellent ground covers.


12.Oxeye daisy

Scientific name: Leucanthemum vulgare

Origin: Europe, Asia

The Oxeye daisy is known by several other names like dog daisy, ox-eye daisy, oxeye daisy, and marguerite. This perennial, grassland wildflower has a yellow center surrounded by multiple petals. The petals are either completely white or in shades of white and yellow. These flowers can be seen on roadsides, ditches, backyards, and other open areas. The daisy-like flowers bloom in summer.


13.Oregon Grape

Scientific name: Mahonia aquifolium

Origin: Western North America

This flowering herb with beautiful bright yellow flowers is mostly grown for its medicinal benefits. Also known as holly-leaved barberry, the Oregon grape belongs to the family Berberidaceae. The dainty flowers bloom in dense clusters in late spring. The fruits of these evergreen plants are round dark blue berries.


14.Oyster Plant Flower

Scientific name: Tragopogon porrifolius

Origin: Mediterranean region

Also known as salsify or vegetable oyster, Oyster plants showy flowers and are grown for their edible roots. The hardy biennial plant flowers in summer. The flowers bloom on tall stalks. The flowers have purple petals that grow like rays from a round center. These flowers when grown in gardens can add the appeal of a wildflower meadow.