Alnus glutinosa
Black alder
How do you recognise black alder?
The leaf tip is notched or blunt, and the leaf is rounder and less serrated than grey alder’s. The bark is dark and cracks into thick plates on an old tree. The male catkins are long, drooping, and yellowish, and the female catkin is shaped like a small cone.
What is it confused with?
Grey alder has a pointed leaf tip and bark that stays pale grey for life. Grey alder also copes with drier ground.
Where does black alder grow, and when does it flower?
Black alder grows in moist, nutrient-rich groves, in the archipelago, along rivers and streams, and on lake shores, and tolerates temporary flooding well. It flowers before the leaves open, in late March or early April in the south.
Can you collect it for a herbarium?
Black alder is common along shores, and a single leafy twig tip is enough. On the label: Note which alder it is, black or grey, because they are two different species.
Did you know?
The female catkin stays on the tree over winter looking like a small cone, which identifies an alder even when it is bare. Black alder stands standing water better than any other tree here.
Where does black alder grow in Finland?
The map shows where the species has been recorded. Darker squares mean more observations.
Loading the map
Observations: GBIF · Map: CARTO, OpenStreetMap
Sources: fi.wikipedia.org
Identify plants with your phone
Linnea identifies a plant from a photo and tells you its name and its story. Every find takes its own numbered place in your herbarium, with the day and the town where you found it.
