How to identify an alder tree
- Common name: European alder
- Latin name: Alnus glutinosa
- Family: Betulaceae
Here's how to identify an alder tree
Alder tree buds
The buds of the alder can be helpful in identifying this tree during the winter and early spring. They are small, softly rounded, and are a delicate, purple colour.
Alder catkins - male
Alder is a monoecious tree This means it has both male and female catkins growing on the same tree. The male catkins are long, slender, soft and turn a beautiful vibrant red as they mature.
Alder catkins - female
The female catkins of the alder are much shorter compared to the male catkins and remain a deep green in colour, criss-crossed by a pattern of lacy black. After fertilization, they swell and expand to form a round knobbly shape.
While the male catkins release pollen, then break up, the female catkins solidify after pollination and mature into hard, woody cones. (The long catkins here are the immature male catkins)
In Britain, there are two types of alder – European alder and black alder. The leaves of the European alder are easy to spot – they are round, wavy-edged and have an indent at the tip. Black alder leaves are not quite as round or wavy and lack the characteristic indent