AlderChase Mathey, CC BY 4.0
Native · Up to 28 m

Alder

Alnus glutinosa · Betulaceae

Also called common alder or black alder

Alder grows by rivers and on wet ground. Its leaves are dark and rounded, and small woody cones hang on its twigs in every month of the year.

Often mistaken for hazel. How to tell them apart →
Know it byLeavesDark, rounded leaves with a blunt, often notched tip.ConesSmall cones in bunches on the twigs, all year.BudsMauve, club-shaped buds, each on its own short stalk.

Then check · BarkAn older trunk is brown and cracked into small, deep square plates, set close together.

How to identify an alder

Alder: leaves
Leaves

Alder leaves are dark, rounded and leathery, and widest near the tip, which is blunt or cut off flat, often with a small notch. The edge is wavy, with small teeth.

Alder: cones
Cones

Small cones hang in bunches on the twigs all year. They are green and soft through summer, then woody and dark brown, and stay on the bare branches all winter.

Learn the alder in TreelyEvery part through the year, and a short round each day until you know it.Get Treely

Every part, in photographs

Alder leaves: racquet-shaped, dark and leathery, tip rounded or notched
LeavesRacquet-shaped, dark and leathery, tip rounded or notched
Alder catkins: catkins on bare twigs in late winterOwen and Carol Fawcett., CC BY 4.0
CatkinsCatkins on bare twigs in late winter
Alder cones: small woody cones, on the tree year roundscallions, CC BY 4.0
ConesSmall woody cones, on the tree year round
Alder bark: brown, in close deep square platesJan Sheppard, CC BY 4.0
BarkBrown, in close deep square plates
Alder twigs and buds: stalked buds, club-shaped and dusted mauveAlexis Tinker-Tsavalas, CC BY 4.0
Twigs and budsStalked buds, club-shaped and dusted mauve
Alder shape: spire when young, broad and twisting when oldChase Mathey, CC BY 4.0
ShapeSpire when young, broad and twisting when old

When to look

JFMAMJJASOND
In leaf
Catkins
Cones

In leaf: April to November · Catkins: August to March · Cones: all year

Every tree on the calendar · How to identify trees in winter

Where you’ll find it

Riverbanks, streamsides, lake and fen edges, bogs, and the wet woodland called alder carr, where it is often the only tree. It grows almost everywhere in Britain and Ireland, and now and then on drier ground.

What it’s mistaken for

Alder: tip of a leafHazel: tip of a leafAlder or hazel?Both have rounded leaves and both hang catkins in late winter.Tip of a leaf Alder: older trunkSilver birch: older trunkAlder or silver birch?Both hang their male catkins in small groups at the shoot tips, and both are in the birch family.Older trunk Alder: fruit on the twigsCommon beech: fruit on the twigsAlder or common beech?Both have leaves with a wavy edge.Fruit on the twigs

More birches, alders, hazel and hornbeam

Downy birchBetula pubescensHazelCorylus avellanaHornbeamCarpinus betulusSilver birchBetula pendula
In the app

There’s more of the alder in Treely

  • Every part, through the yearLeaves, bark, buds, flowers and fruit, photographed in every season
  • Its lookalikes, side by sideThe checks that settle it, part by part
  • A short round each dayUntil you know the alder on sight, from any side
  • Name it from a photoA leaf, the bark or a flower, and Treely tells you which tree
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Every fact on this page is checked against the Collins Tree Guide, last in November 2026. Spotted something that looks wrong in front of a real tree? Tell us. How we check.

Photographs: Chase Mathey (CC BY 4.0), nick88 (CC0), Leon Cross (CC BY 4.0), Alexis Tinker-Tsavalas (CC BY 4.0), steve_mcwilliam (CC0), Owen and Carol Fawcett. (CC BY 4.0), scallions (CC BY 4.0), Jan Sheppard (CC BY 4.0), sim_elliott (CC0). With thanks to everyone who shares their photographs on iNaturalist and Wikimedia Commons.