Alnus incana
Grey alder
How do you recognise grey alder?
The leaves are green and oval, 5–11 cm long and 4–8 cm wide, with a pointed tip. The bark stays pale grey for the whole life of the tree. The male catkins are 5–10 cm long and pale brown.
What is it confused with?
Black alder has a notched or blunt leaf tip and a rounder, less serrated leaf. Its bark is darker and cracks into thick plates on an old tree.
Where does grey alder grow, and when does it flower?
Grey alder favours calcareous, nutrient-rich, moist ground, but copes with drier soil than black alder. It is common on shores, along ditches, and in groves.
Can you collect it for a herbarium?
Grey alder is common, and a single leafy twig tip is enough. On the label: Note which alder it is, grey or black, because they are two different species.
Did you know?
Alders are the only trees here that drop their leaves while still green. Bacteria in their root nodules fix nitrogen from the air, so the tree has no need to save the nitrogen in its chlorophyll over winter.
Where does grey 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.
