Plants That Start With O

Last Updated on January 5, 2023 by Derek

Plants beginning with the letter O
What is a flower that starts with an O? Orchid is the best known flower that begins with the letter O

Name a letter in the alphabet and there’ll be hundreds of plants on this luscious planet that begin with that letter. The letter ‘O’ has plenty of plants that fall under this category.

Here is a list of the plants beginning with O featured in this article:

List of plants that begin with letter O

  1. Orchid
  2. Oak Tree
  3. Olive
  4. Onion
  5. Oleander
  6. Okra
  7. Oregano
  8. Ophiopogon
  9. Ostrich Fern
  10. Ornamental Pomegranate
  11. Orange Jasmine
  12. Osmanthus

Video – Orchid care for beginners

How to care for Orchids

Whether the names of the plants are in plain-old English or have a scientific name associated with them, there are plenty to choose from. With that in mind, let’s have a look at our guide towards the plants of Earth beginning with the letter ‘O’.

Orchid – Orchidaceae

Are Orchid flowers edible?
How long do orchid flowers last? Orchid flowers can last from 8 weeks to 4 or 5 months!

The first plant that would come to anyone’s mind when thinking of the letter ‘O’ is the orchid. Along with Asteraceae, the Orchid family is one of the top 2 largest families in the world with around 28,000 currently accepted species, distributed in about 763 genera.

It is still unclear which of the two families is the largest. Originally native to regions in Asia, Australia, the Philippines, and the Himalayas, the Orchid plant’s timeline begins around 112 million years ago. 

Orchids are easily identified from other plants because of their bilateral symmetry and extremely small seeds. Bilateral symmetry is when an organism or, in this case, a plant has approximately identical features in two mirrored parts. 

Oak Tree

Oak tree scientific name is Quercus
What is an oak tree known for? It is hardy, strong and a symbol of wisdom.

The largest plant on the list, the oak tree is admired by many as wise and strong. Standing tall, the biggest oak in the US was clocked in at a humongous 61m, the equivalent of over 200 feet.

The trunk alone was 44m in height, the same as 145 feet! Fossil records reveal that trees similar to oaks first appeared around 35 million years ago, originating in Asia Minor and Northern Africa. Identified by their fruit, the acorn, oak trees can live to around 1,000 years.

However, scientists believe that a veteran oak is usually around 150-300 years of age. All oak trees are considered ‘ancient’ after living for 400 years.

Olive tree plant

Olive tree - Scientific name: Olea europaea
Is an olive tree easy to care for? Yes, olive trees are low-maintenance plants.

A sub-tropical tree from the Oleaceae family, the olive tree is recognizable with its edible fruit and its broad leaves.

Originating from the Greek island of Crete in approximately 3,500 BC, the olive tree is often praised for its beauty and aesthetic properties. Olive oil was then developed to anoint the body in Ancient Greece, later followed by the Romans in around 600 BC.

Where do olive trees grow best?

Taking these countries by storm, the olive tree then spread to all of the countries encircling the Mediterranean, being used for the fruits of its labor and its ornamental properties.

The olive tree ranges in height from anywhere between 3 and 12 meters with dark green and silvery colors to its leather-like leaves. The wood of the tree is resistant to decay, with the plant able to regrow from the same roots.


Onion family - onion benefits
Is onion a vegetable or spice? The onion is a vegetable from the Allium genus.

The onion has become an international food used all around the world. From the burgers of America to the pasta of Italy, to the traditional rice dishes of eastern Asia, this plant has become a stalwart in the food world.

Onions were originally native to Ancient Egypt and were grown for the edible bulb in around 3,500 BC. however, the plant then spread to India and China 500 about 500 years later, before appearing in Sumeria in 3,500 BC, when people started using the vegetable for food.

The onion was introduced to America after being brought to the West Indies by Spanish explorers, before being implemented in America. Onions come in all shapes and sizes, with red and white onions being the two most common types.

Oleander flower

What are the uses and benefits of oleander? Traditionally used for home remedies for epilepsy, heart issues and even cancer!

This mainly pink plant is a dense and quick-growing evergreen shrub that is hugely recognizable due to its bright colors and pretty presentation.

Since ancient times, the oleander plant has been known to be poisonous to humans and pets, becoming very dangerous if ingested.

Coming from North Africa and the eastern Mediterranean regions, the oleander belongs to the Apocynaceae family and grows to at least 2 meters tall, with 6 meters being the highest typically.

This plant is usually grown as a shrub but can be trained to be grown as a tree with a singular trunk. Because of its origins, the oleander is tolerant to both drought and undulation, but not to prolonged spells of frost. 


How long does it take to grow okra? Okra is ready for harvesting in 50 to 65 days.

Referred to in many English-speaking countries as Ladies’ Fingers’ or ochro, this plant belongs to the mallow family. Used frequently for its edible green seed pods, the okra is a great source of vitamins, antioxidants, and fiber.

The plant is believed to have originated in areas such as Asia, Ethiopia, and other parts of Africa. Okra is grown in tropical, subtropical, and warm temperate climates to suit its natural origins.

Known to many different countries for its edible qualities, the okra is a distinguished part of cuisine in a lot of Southern United States dishes, as well as in Middle Eastern and Indian cuisine.

The first recorded cases of the okra being cultivated were by Ancient Egyptians in the 12th Century BC, before moving to North Africa and the Middle East. The seeds are still used as a coffee substitute to this day!


What is the plant oregano good for? Oregano can help to fight bacteria and reduce infections.

A perennial herb originating from the hills of the Mediterranean and western Asia, the plant has since naturalized in parts of Mexico and the US. Used thoroughly throughout the cooking world, oregano is crucial to many dishes – a lot of them coming from Mediterranean cuisine.

The plant itself grows with rose-purple and white flowers, thriving indoors when given enough sunlight. Oregano well-suits hot, dry, and sunny places due to its ancestral roots.

The Ancient Greeks originally believed that the herb was created by the Goddess Aphrodite as a symbol of joy growing in her garden!


Is ophiopogon Hardy? Yes, they are classed as grassy hardy perennials.

Despite its grass-like appearance, this plant isn’t closely related to true grasses, like the Poaceae. The name ‘ophiopogon’ derives from Greek ‘ophis’ or ‘snake’, and ‘pogo’ or ‘beard’ – referring to the plant’s distinct leaves and tufted growth.

More commonly known as mondo grass or lily turf, this tuberous-rooted member of the lily family usually grows in clumps, that slowly spread and grow to be about 8”-12” tall.

Originating in Japan in around 300 AD, the ophiopogon was used in Ancient China as a cure for ‘heat in the heart’, a condition which is thought to be a build-up of bodily fluids within the human body.

Ostrich Fern

Are ostrich ferns easy to grow? Yes, very easy. Really hardy, they’ll keep coming back in the spring.

Scientifically known as Matteuccia struthiopteris, the ostrich fern is native to temperate regions in North America, Europe, and northern Asia. Highly reliant on water and other minerals to survive, this green shrub is usually found in wooded river areas and bottomland.

Unlike a lot of other plants on this list, the ostrich fern is not evergreen, meaning that it’s not seen throughout every season. When the frost appears in winter, the ostrich fern dies before reappearing vigorously in early spring – sprouting almost overnight! 

Ornamental Pomegranate

Ornamental Pomegranate
Can you eat ornamental pomegranate? Yes, you can, but it isn’t a very nice taste. It’s for ornament mostly.

When looking at a plant’s first appearance in history, the best thing to do is to look out for literary records and archeo-botanical samples to find their oldest form.

The pomegranate seems like it was introduced into the human culture around 5,000 years ago. Used especially for its edible features, wild pomegranate grows in a lot of areas throughout Asia from northern India, to Iran and Turkmenistan.

In recent years, California has been the largest pomegranate growing state in the US. The Spanish Conquistadores brought the fruit to America in the 18th Century, with the original intent of using them for decoration.

Orange Jasmine

Orange Jasmine
What does orange jasmine smell like? It actually smells like orange blossom flowers, hence it’s name!

Belonging to the Rutaceae family, the orange jasmine fills the air with a sweet smell of fresh orange and is frequently used in tropical gardens. Evergreen, this plant’s leaves usually grow to around 3 inches long, with distinctive branches.

The plant itself reaches maturity within around 3 or 4 years, growing from 8 to 12 inches tall and wide. Groups of pretty flowers bloom in the spring, with berries sprouting in the summer.

Don’t be fooled though, the berries and the sap from the orange jasmine are toxic to humans and pets alike.


What is osmanthus used for? Osmanthus is used as a detoxifying tea in some parts of the world.

The osmanthus was originally native to the Himalayan mountains, found more than 1,200 meters above sea level. Cultivated in China, Taiwan, and south Japan, this plant is a large and uptight shrub with evergreen dark green leaves, that grow to around 15cm long.

The small tree produces a small fruit that is non-toxic to humans and animals, coming in the form of black and dark blue berries. Belonging to the Oleaceae family, this plant is often used in China, and other Asian regions, to create cassia wine, a sweet alcoholic drink distilled with an alcohol content of less than 20%.

Shrubs beginning with O

  • Olea
  • Olearia
  • Osmanthus
  • Origanum

Types of trees that start with O

  1. Orange
  2. Orchid tree
  3. Oysterwood
  4. Olive
  5. Osage orange
  6. Oleander
  7. Oak
  8. Orange jasmine
  9. Oleaster

Mushrooms that start with O

  1. Omphalotus olearius
    (Jack O’Lantern(
  2. Oak Maze Gill
    (Daedalea quercina)
  3. Ochre Spreading Tooth
    (Steccherinum ochraceum)

Flowers that start with O

  1. Oriental lily (Lilium orientalis)
  2. Ornamental onion (Allium sp.)
  3. Oriental poppy (Papaver orientale)
  4. Oxeye daisy (Leucanthemum vulgare)
  5. Ocean pearls (Agrostemma githago)
  6. Orlaya (Orlaya grandiflora)
  7. Osteospermum (Dimorphotheca ecklonis)
  8. Ornithogalum (Ornithogalum sp.)
  9. Obedient plant (Physostegia sp.)

Final Thoughts about plants that start with O

The letter ‘O’ is home to many plants of many shapes and sizes, coming from all over the globe. Some have immense nutritional properties, being used in food dishes from all cultures and cuisines.

Others have poisonous tendencies that are harmful to those that ingest their fruits. With lots of different colors involved, there’s a huge mixture ranging from dark green and black, to white and vibrant pink.

The variety we have at our doorstep is incredible, finding new species every day!

FAQ relating to plants starting with the letter O:

What are some examples of plants that start with the letter O?

  • Some examples of plants that start with the letter O include oak trees, olive trees, orange trees, Osage orange trees, and oysterwood trees.

What are the characteristics of plants that start with the letter O?

  • The characteristics of plants that start with the letter O vary depending on the specific plant. Oak trees are known for their strong wood and distinctive leaves, while olive trees are known for their edible fruit and hardy nature. Orange trees are known for their juicy, sweet fruit, while Osage orange trees are known for their hard, yellowish wood and inedible fruit. Oysterwood trees are known for their hard, dense wood, which is used in construction and furniture-making.

Are there any medicinal uses for plants that start with the letter O?

  • Some plants that start with the letter O have medicinal uses. For example, the bark of oak trees has been used as a natural remedy for various ailments, including diarrhea and fevers. Olive oil has been used for centuries as a natural skin moisturizer and hair conditioner. Orange peel has been used to treat digestive issues and skin conditions.

Are there any plants that start with the letter O that are poisonous or toxic?

  • Some plants that start with the letter O may be toxic if ingested. For example, the leaves and bark of oak trees contain tannins, which can cause digestive problems if consumed in large amounts. The fruit of Osage orange trees is inedible and may cause digestive issues if eaten. It is important to familiarize yourself with the characteristics and potential risks of any plant before handling or consuming it.
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