European black alder USDA PLANTS Symbol: ALGL2
U.S. Nativity: Exotic
Habit: Hardwood Trees
Alnus glutinosa (L.) Gaertn.

Jump to: Resources | Images | Distribution Maps | Sources
Taxonomic Rank: Magnoliopsida: Fagales: Betulaceae
Synonym(s): black alder
Native Range: Europe to Cauc. And Siberia, N. Africa (REHD); Europe, North Africa, Asia (BAIL);

Appearance
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.
Foliage
The leaves are simple, alternate and doubly-toothed.
Flowers
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.
Fruit
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.

Identification, Biology, Control and Management Resources

Selected Images from Invasive.orgView All Images at Invasive.org


Tree(s); habitat
Robert Vidéki, Doronicum Kft., Bugwood.org
Additional Resolutions & Image Usage

Tree(s); Urtica kioviensis; habitat
Robert Vidéki, Doronicum Kft., Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Paul Wray, Iowa State University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Paul Wray, Iowa State University, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Paul Wray, Iowa State University, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Additional Resolutions & Image Usage

Fruit(s);
Paul Wray, Iowa State University, Bugwood.org
Additional Resolutions & Image Usage

Fruit(s);
Piero Amorati, ICCroce - Casalecchio di Reno, Bugwood.org
Additional Resolutions & Image Usage

Fruit(s);
Piero Amorati, ICCroce - Casalecchio di Reno, Bugwood.org
Additional Resolutions & Image Usage

Twig(s)/Shoot(s);
Paul Wray, Iowa State University, Bugwood.org
Additional Resolutions & Image Usage

Foliage; flower
Robert Vidéki, Doronicum Kft., Bugwood.org
Additional Resolutions & Image Usage

Flower(s); Male flowers. Poland
Gil Wojciech, Polish Forest Research Institute, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.


Invasive Listing Sources:
City of Ann Arbor Michigan Parks and Recreation
Faith Campbell, 1998
Hoffman, R. & K. Kearns, Eds. 1997. Wisconsin manual of control recommendations for ecologically invasive plants. Wisconsin Dept. Natural Resources, Bureau of Endangered Resources. Madison, Wisconsin. 102pp.
Indiana Native Plant and Wildflower Society
Mid-Atlantic Exotic Pest Plant Council, 2005
Reichard, Sarah. 1994.  Assessing the potential of invasiveness in woody plants introduced in North America. University of Washington Ph.D. dissertation.