[3] It is a large shrub or small tree 3–12 metres (10–39+1⁄2 ft) tall with smooth grey bark even in old age.

[5] A study in Alaska showed that Sitka alder seedlings were able to invade coal mine spoils and can be used for revegetation and stripmine reclamation.

[6] There are four to six subspecies, some treated as separate species by some authors:[7] Alnus viridis is classed as an environmental weed in New Zealand.

It is sometimes used for afforestation on infertile soils which it enriches by means of its nitrogen-fixing nodules, while not growing large enough to compete with the intended timber crop.

[9] Alnus viridis leaves have been used in the traditional Austrian medicine externally or internally as tea for treatment of infections and fever.