It thrives in wet locations where its association with the bacterium Frankia alni enables it to grow in poor quality soils.

The common alder provides food and shelter for wildlife, with a number of insects, lichens and fungi being completely dependent on the tree.

The timber has been used in underwater foundations and for manufacture of paper and fibreboard, for smoking foods, for joinery, turnery and carving.

Products of the tree have been used in ethnobotany, providing folk remedies for various ailments, and research has shown that extracts of the seeds are active against pathogenic bacteria.

A. glutinosa is a tree that thrives in moist soils, and grows under favourable circumstances to a height of 20 to 30 metres (66 to 98 feet) and exceptionally up to 37 m (121 ft).

[5] The leaves of the common alder are short-stalked, rounded, up to 10 centimetres (4 inches) long with a slightly wedge-shaped base and a wavy, serrated margin.

During the autumn they become dark brown to black in colour, hard, somewhat woody, and superficially similar to small conifer cones.

This means that as a tree in woodland grows taller, the lower branches die and soon decay, leaving a small crown and unbranched trunk.

[10] Its present scientific name is due to Joseph Gaertner, who in 1791 accepted the separation of alders from birches, and transferred the species to Alnus.

[14] The common alder is native to almost the whole of continental Europe (except for both the extreme north and south) as well as the United Kingdom and Ireland.

[16] Its natural habitat is in moist ground near rivers, ponds and lakes but it can also grow in drier locations and sometimes occurs in mixed woodland and on forest edges.

[16][17] European alder does not usually grow in areas where the average daily temperature is above freezing for longer than six months; its range is mainly restricted in Scandinavia, but it also habitats other regions.

[17]The common alder is most noted for its symbiotic relationship with the bacterium Frankia alni, which forms nodules on the tree's roots.

This relationship, which improves the fertility of the soil, has established the common alder as an important pioneer species in ecological succession.

[18] The common alder is susceptible to Phytophthora alni, a recently evolved species of oomycete plant pathogen probably of hybrid origin.

[16] Taphrina alni is a fungal plant pathogen that causes alder tongue gall, a chemically induced distortion of female catkins.

Some common lichens found growing on the trunk and branches include tree lungwort (Lobaria pulmonaria), Menneguzzia terebrata and Stenocybe pullatula, the last of which is restricted to alders.

[21] Some 47 species of mycorrhizal fungi have been found growing in symbiosis with the common alder, both partners benefiting from an exchange of nutrients.

It is a fast-growing tree and can quickly form dense woods where little light reaches the ground, and this may inhibit the growth of native plants.

It spreads easily by wind-borne seed, may be dispersed to a certain extent by birds and the woody fruits can float away from the parent tree.

As the pollen is often present in the atmosphere at the same time as that of birch, hazel, hornbeam and oak, and they have similar physicochemical properties, it is difficult to separate out their individual effects.

It is also valued in turnery, carving, furniture making, window frames, clogs, toys, blocks, pencils and bowls.

[30] It exhibits a balanced, even tone with a good mid-midrange projection making it suitable for a wide variety of musical applications.

[32] Depending on the mordant and the methods used, various shades of brown, fawn, and yellowish-orange hues can be imparted to wool, cotton and silk.

[32] In a research study, extracts from the seeds of the common alder have been found to be active against all the eight pathogenic bacteria against which they were tested, which included Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA).