Common alder or Green alder: how to tell them apart?
Common alder and Green alder look alike and are often mixed up. Here is how to tell them apart, feature by feature, with their photos and the details to look for.
⚡ The quick answer
Common alder
Alnus glutinosa
Green alder
Alnus viridis
Green alder remains a low, bushy shrub of mountain slopes, with pointed, glossy leaves, whereas common alder is a large riverbank tree with rounded leaves that feel slightly sticky to the touch.
🍃 Leaves
Rounded to ovate, often truncated or notched at the tip; young leaves sometimes sticky.
Deciduous, rounded, doubly toothed, bright glossy green above
🌸 Flowers
Long hanging male catkins and small reddish female catkins
Hanging yellowish male catkins (4 to 8 cm), smaller upright female catkins, grouped in 3 to 10
🍎 Fruits
Small brown woody cones persisting all winter
Small ovoid woody cones persisting on the branches in winter
🪵 Bark
Brown-black, cracking into small plates
Grey and smooth, supple shoots forming thickets that are hard to cross
📏 Size
20 to 25 m tall
1 to 4 m tall, exceptionally up to 8 m
🗺️ Habitat
Riverbanks, wetlands and marshy areas
Damp slopes, snowbeds and high-altitude pastures of the Alps, often in dense thickets in the subalpine zone
⚠️ Toxicity
No known toxicity
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🔎 And from the Green alder side
Common alder is a large riverbank tree with rounded, slightly sticky leaves, whereas green alder remains a low, bushy shrub typical of mountain slopes, with pointed, glossy leaves.
🌿 Go further
Want to practise spotting these details on real photos? Floraneo offers profiles and quizzes for dozens of look-alike species.
ℹ️ Educational profile — do not use it to judge whether a plant is edible or safe.