How to Identify Different Types of Oak Trees: A Complete Guide

types of oak trees

Oak trees are among the most popular trees in North America mainly because their leaves can absorb large amounts of airborne pollutants including carbon dioxide and release large amounts of the essential oxygen through photosynthesis to keep the air clean and healthy.

But if you are planning to plant oak trees in your garden, you need to start by understanding the different varieties of oak trees available. Continue reading to know how to identify different types of oak trees.

Introduction to Oak Trees

Introduction

An oak tree belongs to the genus Quercus of the beech family, commonly referred to as Fagaceae. Currently, there are over 500 species of oak trees in the world, with North America playing host to the largest number of oak species. The Quercus class of trees is commonly found in the Northern Hemisphere, which includes deciduous and perennial species.

It extends from cool moderate to tropical latitudes in the Americas, Europe, Asia, and North Africa. The second biggest center of oak trees in China, where you will find about 100 species of oak. Most species of oak have spirally arranged leaves with lobate margins.

But there are some oak species with jagged leaves and others with leaves that have smooth margins. Most of the deciduous oak species do not drop their leaves until the spring season sets in. It is also important to understand that oak trees are monoecious. That’s why one oak tree can produce both male and female flowers.

This tree produces fruits carried in cup-like structures called cupules. These fruits are referred to as acorns and are pure nuts. Each acorn has two or three seeds and takes approximately 18 months to mature. Acorns and oak leaves have tannic acid, which is commonly used to deal with fungi and pest infestation.

An oak tree can grow to over 100 feet (30 meters) tall and is also considered to be one of the strongest trees in the world.

History of Oak Trees

History of Oak Trees

Although it is not very clear how and when oak trees came to be, it is evident that oak trees have been around for a very long time.

According to studies, members of the Fagaceae family have been around since the Late Cretaceous, which happened some 85 million years ago. But the first fossils of an oak tree to be recorded in history appears about 35 million years ago.

These fossils indicate that the actual oak species (similar to the modern-day oak trees) appeared some 25 million years ago. This record makes oak trees one of the oldest trees on earth. But where exactly did this tree originate from?

Since the oldest fossils of oak were discovered in the present-day state of Georgia, America has every right to claim oak trees to have originated in the United States.

Furthermore, all the over 500 species of oak trees are native to the northern hemisphere, with the largest number of these species coming from North America.

How to Identify an Oak Tree?

How to Identify an Oak Tree

Oak trees are among the most popular ornamental trees in America and other parts of the world. That’s why their demand continues to grow every day, with many property owners planting different varieties of oak to add value and beauty to their properties. However, not every oak tree will give you what you want.

So, you need to know what each species of oak looks like and what to expect from it. Fortunately, you can easily tell the difference between different types of oak trees by simply studying the shape and size of their leaves. Apart from leaves, there are several other unique characteristics of an oak tree that you can look out for.

The Appearance of an Oak Tree

It is almost impossible to overlook an oak tree, especially because of its majestic branches that cover a large area around the tree. Another distinctive feature of an oak tree is its giant height. As mentioned above, most oak tree species can reach heights of approximately 100 feet and can extend to about 150 feet wide.

Leaves

Most oak species have leaves with an elliptical shape and a solid stem. However, their sizes range from 2 to 5 inches wide. The upper part of an oak leaf is dark green with a glossy texture. Its bottom part is dull grey and feels fibrous to the touch. In the fall, oak leaves turn orange, yellow, and red.

Bark

As an oak tree grows old, its bark takes a life of its own, turning from a dark brown color to a reddish tinge and black. It also develops grooves and flaking bridges as the tree grows old.

Fruit

As indicated above, oak trees produce fruits known as acorns. These fruits are brown and have a bitter taste when raw. But their taste improves once they are roasted. A mature acorn doesn’t grow more than 1-inch long.

Acorns are either attached to the tree or grow in clusters. Oak trees don’t produce fruits until their 20th season of development. Some species of oak can go up to five decades before they produce their first fruits.

7 Types of Oak Trees

Most Common Types of Oak Trees

1. Red Oak (Quercus rubra)

Red Oak

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Red oak is a deciduous tree (shedding its leaves annually). Its main characteristic is the bright red leaves. This oak tree is also recognizable by its thick golden hairs that grow along the base of its leaves.

Red oak also produces white flowers in spring that are pollinated by different insects to form acorns. This oak tree is widespread in the Eastern United States. It can grow up to 100 feet tall and live for about 300 years.

Compared to other types of oak trees, red oak grows faster and forms an open canopy. A growing red oak tree has smooth bark with a silver color appearance. But its bark develops ridges and turns dark as it ages.

2. White Oak (Quercus alba)

White Oak

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The white oak is one of the famous hardwoods of eastern and central North America. It is also one of the most long-lasting oak trees on earth, with some of its specimens reported to be over 450 years old. Contrary to what its name suggests, this oak tree has a light grey bark. The name ‘white’ refers to its finished wood.

The white oak tree typically grows up to 100 feet tall and about 80 feet wide. It can even grow taller than 100 feet in the forest where it is competing for light with other tall trees. This oak tree doesn’t produce acorns until the 50th season of its growth.

In spring, its delicate clustered leaves turn silvery pink. As the season progresses, their opalescent appearance turns into a soft pink, then a silvery-white, and finally into a yellow-green shade. Its leaves can grow up to 8.5 inches long and 4.5 inches wide.

Other Types of Oak Trees

3. Pink Oak (Quercus palustris)

Pink Oak

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This is a pyramid-shaped oak tree that will form an outstanding focal point in your garden. A mature pink oak tree can grow up to 70 feet tall and spread its branches up to 40 feet wide. The tree also has lobed leaves that turn bright crimson-red and reddish-brown in autumn.

This type of oak tree is common in eastern and central North America. Pink oak is a darling of many gardeners because of its stunning beauty and endurance of harsh growing conditions. This tree can resist the effects of harsh winds and storms.

The pink oak leaves are between 3 and 6 inches long with about 7 lobes separated by deep sinuses. Their upper part is bright and glossy, while their underside is pale. The sinuses, which change color in fall to red and brown, take a smooth round shape.

Pink oak thrives in hardiness zones 4 to 8 and its acorns are a half-inch long with saucer-like caps. The tree’s red-grey bark is slightly textured and becomes rougher as it grows old.

4. Japanese Evergreen Oak (Quercus falcata)

Japanese Evergreen Oak

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The Japanese evergreen oak tree grows pretty fast compared to other types of oak trees. This makes it a great choice for gardeners who wish to add an element of nature to their gardens. The tree is popular for its amazing fall purple-brown color, which is more vibrant than its spring leaves.

This oak tree grows up to 45 feet tall and 20 feet wide. It prefers a warm coastal environment, but it can also do well in an inland environment. The Japanese evergreen oak tree is resistant to harsh weather conditions, which makes it the ideal choice for gardeners in urban areas.

Its small and dense growth makes it the ideal choice for anyone looking for a natural sunscreen or small shade tree. Its leaves can grow up to 5 inches long and have tips that are evenly rounded with elongated points. The tree’s bark is smooth with multiple branches, but it becomes rough as the tree grows old.

5. Sessile Oak (Quercus petraea)

Sessile Oak

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The sessile oak tree is very popular in Europe and North America. It grows up to 30 feet tall and about 20 feet wide. Unlike many other types of oak trees, sessile oak grows very fast, reaching about 6 feet tall in one year.

Its leaves are dark green with an oval shape and can grow up to 8 inches long. Sometimes its leaves are heart-shaped with rounded edges. The tree’s bark can be grey or brown and quite rough. Its flowers are green and about 1/8-inch wide. This oak’s acorns grow up to 1/3-inch long.

6. Post Oak (Quercus stellata)

Post Oak

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The post oak is a dense tree with an oval crown and rough branches. This type of oak tree is popular for its high-quality and durable wood, which has always been used in designing railroad crossties, utility posts, and other important constructions. It also has a very narrow, V-shaped trunk that forms a low, open, curved crown.

Post oak leaves are narrow and long with stems that sink into the leaves. These leaves also appear in a cluster of three at the edge of the branch and have sharp margins. The texture of these leaves is leathery dark with wide cross-like lobes.

A post oak tree can grow up to 40 feet tall and 15 feet wide. Its trunk is fairly thick and great for small gardens.

7. Scarlet Oak (Quercus coccinea)

Scarlet Oak

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A scarlet oak tree grows up to 50 feet tall and 30 feet wide. It’s a deciduous tree that grows in different parts of the world, including eastern North America and the Atlantic coast. Since this is a hardy tree, you can find it thriving in different types of climates and soils.

Its acorns ripen in autumn, and their seeds are spread by squirrels and other wild animals. This oak tree has thick leaves with a leathery and shiny upper surface and unevenly undulating margins. The leaves, which grow up to 7 inches long grow on stalks that are about 1-inch long.

These leaves are also lobed with a hand-like shape. Their upper side is very smooth, while their underside is hairy around the edges. The tree’s trunk is short and forms a curved canopy. The trunk is also dense and more compact at the tip than the bottom. Its bark is grey with deep furrows.

In Summary

With this information, you should be able to choose the right types of oak trees for your garden. Make sure you choose oak trees that will survive the weather conditions in your area and give you the kind of benefits you are looking for.

Britni Luczak
Britni Luczak is a web expert known for her out-of-the-box take on all things digital. She regularly writes as a guest author on many blogs, and is keenly interested in helping small businesses and entrepreneurs outgrow their legacy roots. Luczak is also an avid reader. She is currently planning to write and launch her first book.