Alder leaf

©Philip Precey

Male Siskin on Alder

Male Siskin on Alder ©Luke Massey/2020VISION


Scientific name: Alnus glutinosa
Common alder can be found along riversides, and in fens and wet woodlands. Its exposed roots provide shelter for fish, and its rounded leaves are food for aquatic insects.

Species information


Height: up to 20m

Conservation status


When to see

January to December


Common alder is a common tree of riversides, fens and wet woodland. The exposed roots of riverside trees provide fish with shelter from predators or high flows, and the leaves provide food for invertebrates, such as the larvae of caddis flies, stoneflies and water beetles. These, in turn, are preyed upon by fish, including Salmon and Brown Trout. The wood of Common alder does not rot under water, so was traditionally used for shoring-up canals and riverbanks. It was also used to make charcoal and clogs!

How to identify

Common alder has both male and female flowers: long, yellow-brown catkins; and small, red 'cones' that ripen and harden when pollinated. It can also be recognised by its rounded leaves and purplish buds.



Did you know?

During the winter, Common alder seeds are a favourite food for visiting and resident Siskins and Lesser redpolls.

How people can help

The Wildlife Trusts manage many wetland nature reserves for the benefit of the wildlife they support. You can help by supporting your local Trust and becoming a member; you'll find out about exciting wildlife news, events on your doorstep and volunteering opportunities, and will be helping local wildlife along the way.