European black alder
Alnus glutinosa (L.) Gaertn.


Alnus glutinosa is a tree in the birch family that can grow up to 50 ft (15.24 m) tall with the crown spreading from 20-40 ft (6.1-12.2 m) wide. It can be single or multi-stemmed, with a smooth greyish-green bark that turns a speckled grayish-brown. It is native across Europe, temperate Asia, and north Africa. It has been planted extensively in North America as an ornamental tree and for erosion control.
The leaves are simple, alternate and doubly-toothed.
The individual flowers are small and inconspicuous individually, but together they form a catkin. They flower in the spring and catkins remain on the trees through the fall.
Fruits are obovate samaras. The wings are reduced to narrow thinkened ridges.
Ecological Threat
A. glutinosa can grow on a wide range of soils has been seen to form monotypic stands. Although it can toleate droughts, it prefers moist, damp conditions, especially near water sources. It commonly grows in riparian zones, wetlands, along ponds and lakes. It also grows in forests, forest wetlands and in urban areas.


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EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Hamamelidae
Order: Fagales
Family: Betulaceae
Genus: Alnus
Subject: Alnus glutinosa (L.) Gaertn.

Synonyms and Other Names

Other Common Names:
black alder


Plants - Hardwood Trees