The Alder Tree (Alnus glutinosa)

The Common Alder is a native riverside tree in the UK and a particularly appropriate choice for our first ‘What’s Growing on the Greenway’ blog. Its branches grow upwards creating a conical shaped medium sized tree which sometimes has two or three main trunks. The twigs can be sticky to the touch which gives rise to the second part of its latin name, glutinosa, (which means sticky!)

The recognisable purple or grey leaf buds form on long stems and develop into dark green racquet-shaped leathery leaves, with serrated edges. Alder has both long, yellow-brown catkins and small, red 'cones' that ripen and harden when pollinated.

Alder is a particularly useful tree due to its relationship with a nitrogen-fixing bacterium called Frankia alni. This bacterium is found in the roots and it collects nitrogen (tree food) from the air and makes it available to the tree. The alder, in turn, provides the bacterium in the ground with sugars. This mutually beneficial relationship allows the alder to grow in challenging riverside locations where other trees wont and improves the fertility of the soil so that other species will be able to grow there in the future.

A great Connswater Community Greenway Tree!

Where to find it?

You will find the common alder all along the Connswater, Loop and Knock river sections of the Greenway:

  • There are 3 Clear Stem Alder trees in Flora Street Walkway at the entrance to Bloomfield Parade
  • From Marshwiggle Way at Orangefield Park to entrance at Clarawood Park
  • Along the river between the Police Station at Alexander Road and Royal British Legion at Montgomery Road.
  • Loop River Play Park

Be Part of it..

If you’re out for a dander we’d love to see your pictures of some of the Alders! Send them in via social media or email

If there’s any trees or plants you’d like to see featured on the blog please let us know.