Alder Facts for Kids

Quick facts for kids Alder

Alnus serrulata (Tag Alder) Male catkins on right, mature female catkins left Johnsonville, South Carolina
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Fagales
Family:	Betulaceae
Genus:	Alnus Mill.
Species
About 20-30 species, see text.

Alder is the common name for a group of trees and shrubs. There are about 30 different kinds, all belonging to the Alnus genus. They are part of the birch family, known as Betulaceae. Most alders are smaller in size compared to other trees. Their leaves usually fall off in autumn (they are deciduous). Only a few types of alders stay green all year (they are evergreen).

Alders grow in many parts of the northern half of the world. You often find them in places with poor soil or wet ground. Their leaves are simple and have a jagged, toothed edge.

How Alders Reproduce
Types of Alders
Uses of Alder Trees
Images for kids
See also

How Alders Reproduce

Alder trees have special flowers called catkins. The male flowers look like long, hanging tassels. The female flowers are much smaller and shaped like tiny cones.

Male catkins (right) and female catkins (left) on a Tag Alder.

The wind carries pollen from the male catkins to the female catkins. This helps the plant make seeds. After the female flowers are pollinated, they grow into small, green, rounded fruits. These fruits look a bit like tiny cones. In autumn, they turn brown and open up to release their seeds.

Types of Alders

There are many different kinds of alders. Some are well-known in certain areas.

The Common Alder is often seen across Europe.
The Red Alder is probably the tallest type. It grows in North America. This tree can reach heights of about 32 to 35 meters (around 100-115 feet).
The Green Alder is a widespread type that is usually a shrub. It rarely grows taller than 5 meters (about 16 feet).
In the United Kingdom, the most common alder is also called the Black Alder or European Alder.

Uses of Alder Trees

Alder trees are important for nature and for people.

They are a favorite tree for bees, especially in the spring when their catkins provide early pollen.
The wood from alder trees can be used to make charcoal. Charcoal is a black material used for things like drawing or fuel.
Alder roots have special bumps called nodules. These nodules help the tree take nitrogen from the air. This makes the soil healthier for other plants too.