Cut-leaved Alder

May 11, 2021 by bo

Alnus glutinosa

Alnus glutinosa is known as the Cut-leaved Alder, and is also known as Black Alder, European Alder or just plain old Alder. It is native to most of Europe as well as southwest Asia and northern Africa. It is a fairly short-lived tree growing to as much as 30 meters tall. It has male and female flowers in the form of catkins. The small, round fruits are a bit like cones bearing the seeds, which are dispersed by both wind and water. They provide both food and shelter for wildlife, with a number of insects, lichens and fungi being completely dependent on these trees. 140 different plant eating insects have been shown to be associated with alder. It is an early coloniser of suitable habitat at woodland edge, marshland and river banks. It thrives in wet woodland and its timber has been historically used for underwater foundations and as coppice. It has also been a favourite wood for smoking food. Used as folk medicine it is now found to have an active ingredient in the seeds that works against pathogens. On the other hand Alder pollen is the second most common cause of ‘hay fever’ after grass pollen.

Because of its association with water it has been used to stabilise river banks, help with flood control and to purify water.

Funky Facts File: The bark has long been used for tanning leather as it contains up to 20% tannic acid… Laplanders are said to chew the bark and use their saliva to tan reindeer leather. Other parts of the tree are also used in dyeing; the catkins give a green colour and the fresh-cut wood a pinkish-fawn one. Alder leaves are sticky and if spread on the floor are said to trap fleas!

Black Alder in Autumn in Dumpton © Bo Beolens
© Giovanni Caudullo Wikimedia Commons