Alnus rubra

The red alder is a very big tree.

It grows near the ocean and rivers. Its bark can turn a rusty red color.

The leaves have edges that curl under. In the fall, the leaves turn dark. They fall off the tree. Small seeds have wings to help them fly.

Deer and elk like to eat the twigs. This tree is very helpful to the forest.

The red alder is a large tree.

It grows in western North America. You can find it near the Pacific coast. It grows on cool, wet slopes or near water.

The bark is gray and smooth. If it gets scraped, it turns a rusty red. This gives the tree its name.

Its leaves are long with edges that curl under. In the fall, the leaves turn dark before they fall. The tree makes small seeds. These seeds have thin wings. The wings help the seeds fly long distances in the wind.

Scientists use these leaves to study air. If there is too much ozone, the leaves turn red or purple.

This tree helps the forest grow. It has tiny parts on its roots called nodules. These nodules hold a germ called Frankia. This germ helps the tree take nitrogen from the air. Nitrogen helps plants grow in poor soil. When the leaves fall, they make the soil better for other plants. Many animals eat the tree. Deer and elk eat the twigs. Small birds and mice eat the seeds.

The red alder is a very special tree from western North America. It is the largest species of alder in North America.

This tree can grow very tall. One official tall tree stands in Clatsop County, Oregon. The trunks can be quite wide too. The bark is smooth and ashy-gray. It often has white lichen or moss growing on it. If you scrape the bark, it turns a rusty red color. This is how the tree got its name.

This tree has a very interesting way of working with the earth. It has tiny bumps on its roots called nodules. These nodules hold a germ named Frankia. This germ helps the tree take nitrogen from the air. Nitrogen is like food that helps plants grow. Because of this, the red alder can grow in poor soil. It is an early colonizer, which means it is often the first tree to grow in new areas.

It can quickly cover areas after a fire or logging. When its leaves fall, they decay and make the soil better for other plants.

Scientists use this tree to learn about the air. The leaves can act like a warning sign. If there is too much ozone pollution, the leaves change color. They might turn red, brown, or even purple.

This helps researchers find areas with high ozone levels. The tree's leaves are also easy to recognize. They are long and have edges that curl under. In the fall, the leaves turn dark before they drop to the ground.

Many living things rely on the red alder for food. Deer and elk eat the twigs in the winter and spring. Some birds, like the common redpoll, eat the seeds. Even deer mice like to eat them too.

The tree makes small, woody fruits that look like tiny cones. These cones hold seeds with thin, paper-like wings. These wings help the seeds fly long distances on the wind. This way, the tree can spread to new places.

People have used the red alder for a long time. Native Americans used the bark to make a red dye. They used it to color fishing nets so they were hard to see underwater. They also used the bark for medicine to treat skin irritations. Today, the wood is used for many things. It is used to make furniture and even electric guitars.

Some people even use the wood to smoke salmon because it makes an oily smoke.

Alnus rubra, commonly known as the red alder, is a deciduous broadleaf tree. It is native to western North America. This region includes Alaska, British Columbia, and parts of the United States like Washington, Oregon, and California. The red alder is the largest alder species in North America. It is also one of the largest in the entire world.

These trees are important for forest ecosystems. They act as early colonizers in disturbed areas. This means they are often the first trees to grow back after a disaster.

The tree has several unique physical features. Its bark is smooth and ashy-gray. It is often covered by white lichen and moss. If the bark is bruised or scraped, it turns a rusty red color. This specific trait gives the tree its name.

The leaves are long and oval-shaped. They have edges that are bluntly serrated. A key way to identify this tree is its revolute leaf margins. This means the very edge of the leaf curls under. In autumn, the leaves do not turn yellow. Instead, they darken in color and wither before they fall.

Red alders have a special way of growing in poor soil. They host a nitrogen-fixing actinomycete called Frankia. This is a type of bacteria that lives in small nodules on the tree's roots. The Frankia works with the tree to take nitrogen from the air. This process allows the red alder to grow in nitrogen-poor soils.

When the leaves fall, they decay quickly. This decay creates a nitrogen-enriched humus. This organic matter makes the soil better for other plant species. Because of this, red alder is a vital part of forest regeneration.

The reproductive cycle of the red alder involves specialized flowers. In early spring, male flowers appear as dangling reddish catkins. These catkins can be up to 10 centimeters long. Female flowers grow in clusters of four to eight. These female flowers are erect during anthesis, which is the period when they are open. They eventually develop into small, woody, cone-like fruits. These fruits are about 1 centimeter long. The seeds grow between the woody bracts of these cones. They are released in late autumn or winter. Each seed has a membranous winged margin. This wing allows the wind to carry the seeds over long distances.

Red alders grow in many different environments. In Alaska and British Columbia, they prefer cool and moist slopes. In California, they usually grow near wetlands or watercourses. They can grow from sea level up to elevations of 1,500 meters. The tree is shade intolerant, meaning it needs sunlight to grow well. Because they produce so many seeds, they can cover disturbed areas very quickly. In the first year after a fire or logging, a single hectare might host several million seedlings.

Humans have used the red alder for many purposes. Native Americans used the bark to create a russet dye. They used this dye on fishing nets to make them less visible underwater. The bark was also used in medicine for skin irritations and insect bites. Some groups, like the Blackfeet, used bark infusions for lymphatic disorders. Today, the wood is used for furniture and cabinetry. It is also valued by musicians. Some builders use red alder for electric guitars because of its balanced tonality.

It is also the preferred wood for smoking salmon due to its oily smoke.

Scientists also use the red alder as a biomonitoring organism. This means the tree helps them study the environment. The leaves react to ozone pollution in the air. If ozone levels are high, the leaves develop red, brown, or purple discolorations.

This makes the tree a living indicator of air quality. In the Pacific Northwest, red alder makes up 60% of the total hardwood volume. This makes it a very significant part of the regional economy and ecology.