Oaks of North America

Oak is the common name given to about 400 species of trees and shrubs in the genus Quercus . The generic name oak derives from the Latin robur . The genus Quercus originates from the northern hemisphere and includes deciduous and evergreen species that range from cold places to tropical Asia, and are found particularly in North America. Oaks can be long-lived (some species can live for hundreds of years) and very tall (they can be up to 20 or 30 meters tall); they are excellent producers of food for the wild animals that eat their acorns.

Many species have spiral leaves, with lobed edges. Other species have serrated or smooth-edged leaves, which are known as whole leaves.

Oak blossoms or catkins fall in late spring; the acorns produced from these flowers are cup- or dome-shaped. Each acorn has at least one seed (in some cases they contain two or three) and takes 6 to 18 months to mature, depending on the species.

Evergreen or hardy oaks are not a different group from oak and we are going to include some of them in the species listed below. Oaks can be classified into red oak and white oak according to the color their wood exhibits when felled.

How to identify them

In summer we can look for its short-stemmed leaves of various shapes, sometimes lobed. Its bark is gray and scaly, or blackish and wrinkled. Its branches are thin with a star-shaped pith. Its acorns fall to the ground in autumn, over the course of a month. And if the tree is stressed, it will drop some acorns in summer, while they are still green, because if the conditions are not suitable for the tree to be able to sustain the development of all the fruits on its branches, it will not have enough energy to make them. to mature.

In winter, oaks can be identified by the five-sided pith of the branches; they have clustered shoots at the tips of the shoots, and have semicircular leaf scars protruding slightly where the leaves were attached to the branches.

In the southern United States, live oak and water oak species retain most of their leaves during the winter. Red oaks have symmetrical leaves at least 10 centimeters long, with points on their lobes and veins extending to the edges, while white oaks have rounded lobes on their leaves, with variably shaped indentations.

Let’s take a look below at 17 species of oak that can be found in North America.

black oak

The black oak is a species whose habitat is the eastern area of ​​North America, from Ontario in Canada to the southern United States, except Florida, and reaches heights of 15 to 35 meters depending on the location. It can adapt to poor soils. Its leaves are shiny or satin, with five to nine lobes ending in one to four teeth. Its bark is dark gray to almost black.

bur oak

Bur oak ranges from Saskatchewan in Canada and Montana, to Texas. It grows up to 25 meters tall and has wide crowns, although it has a more bushy development in the northern and eastern parts of its habitat. It is one of the most drought resistant oaks. The leaves are elliptical in shape, with five to seven rounded lobes. The cap of the acorns is scaled at its junction to the seed, covering half or more of its surface.

cherry oak

Cherry oak can often reach 30 meters in height. It is fast growing and its leaves are glossy and dark green in color with five to seven lobes extending at right angles from the center and ending in one to three teeth. Cherry oak grows from Maryland to Texas, and from Illinois to the Florida panhandle in the United States.

chestnut oak

The chestnut oak reaches 20 to 45 meters in height. Its leaves are barely veined, with 10 to 14 teeth instead of lobes. The acorn cap has gray scales tipped with red, covering an oval seed. The tree is found in upland rocky forests and dry soil, from Ontario and Louisiana to Georgia and Maine.

bay oak

Bay oak leaves do not have the typical appearance of oak leaves. Its leaves are narrow, similar to those of the laurel from which it takes its name. This tree can reach 30 meters in height. Its acorns are dark brown to black in color and less than two centimeters long, with a cap that covers up to a third of the seed.

live oak

Live oak is evergreen and inhabits southern North America. Iconic images of large trees on mossy sandy soils are often live oak. These trees can live for hundreds of years and grow rapidly when young, reaching a height of 10 to 20 meters with a spread of 20 to 30 meters. They have thin, short leaves, and the acorns are oval, dark brown, almost black.

northern red oak

Northern red oak grows to a height of 20 to 45 meters. Its wood is orange-red in color, with a straight grain. They are fast growing and develop in compacted soils. The leaves have seven to eleven lobes with one to three teeth and veins that reach mid-distance from their center. The acorn cap covers about half of the seed. These trees grow from Maine and Michigan to Mississippi, in the United States.

Oak overcup

The overcup oak is a slow-growing tree that reaches a height of 25 meters. Its leaves are dark green in color, have a long vein with rounded lobes with one to three teeth that can be shiny. The base of the tree trunk is grayish-green in color and has a whitish flower that comes off when rubbed. The acorns are light brown in color and the cap covers most of the nut. These trees are found in lowlands on the southern coast of the United States, and along rivers in the south and west.

pin oak

The pin oak has its lower branches drooping downward. They can reach a height between 20 and 40 meters. The interior of its bark is pink; its leaves have deep veins that spread into five to seven lobes with one to three teeth. The acorn cap covers only a quarter of a round seed and has small scales.

pole oak

Pole oak is a slow-growing tree that can reach 15 to 30 meters in height. It has leaves with five to seven smooth lobes. The acorns are round with wart-like markings, and the caps cover one-fourth to two-thirds of the seed. These trees are found throughout the southern United States, stretching from Texas to New Jersey.

scarlet oak

Scarlet oak is drought tolerant and grows best in sandy soil. Its leaves have C-shaped veins between the lobes, which vary in depth even within the same tree. These trees grow to be 12 to 15 meters tall. The cap of its acorns is very shiny and the bark is light to dark gray.

Shumard Oak

Shumard oak is among the southern red oaks, reaching 45 meters in height. It grows in soils near rivers and streams, from Ontario in Canada to Florida in the southern United States, and from Nebraska to Texas. The leaves have five to nine lobes with two to five teeth, with deep veins. The cap of the acorns covers up to a third of the seeds.

Southern Red Oak or Spanish Oak

Southern red oak, also called Spanish oak, grows in the United States from New Jersey to Florida, and west to Oklahoma and Texas. It reaches heights of 20 to 30 meters. Its leaves have only three lobes. It grows preferentially on sandy soils. The acorns are roundish, brown in color, and have a thin cap that covers up to a third of the seed.

bog chestnut oak

The bog chestnut oak grows to heights ranging from 15 to 50 meters. It prefers moist soils and flooded plains. They are found in the United States in central and southern forests from Illinois to New Jersey, and from Florida to Texas. Its leaves are wide and wavy with between nine and fourteen rounded teeth, ending in a point. The acorns are brown in color and egg-shaped, and their caps are bowl-shaped.

water oak

The water oak retains most of its leaves during the winter. It is found in the southern United States, from Texas to Maryland. They are trees that cast extensive shadow and reach 30 meters in height. Its leaves are lobed or toothed. The caps of the acorns cover only a quarter of the seed.

White Oak

White oak is a long-lived tree, casting extensive shade and growing to heights of 20 to 45 meters. Its leaves have rounded, highly toothed lobes; they are grayish-green in color and are broader towards their end. The caps of the acorns are light gray in color and cover only a quarter of a light brown seed. White oak is found from Quebec, Ontario, Minnesota, and Maine, to Texas and Florida.

willow oak

Willow oak leaves are not shaped like one would imagine on an oak tree; these are thin and straight, about two centimeters wide, and have no lobes. The height of these trees can reach 40 meters. They are found along rivers, mainly in the southern United States. Its acorns are dark in color and have faint stripes.

Fountain

• Owen Johnson, David More. Spanish version of the  Collins Tree Guide . Ed Omega, 2006.