Black Alder, also called European Alder or European Black Alder (Alnus glutinosa Gaerten, Family Betulaceae)

Description of Plant

Leaf: Found in 3 rows, 1 1/4 - 4" long, 1- 2 1/2' wide; eliptical to nearly round; doubly saw-toothed with 5 to 7 parallel veins on each side.

Flower: Male catkins are 1 - 1 1/2" long, female flowers which are found in the cones are 1/4" long.

Cones: 5/8 - 7/8" long, in clusters of 3 to 5; eliptical or egg-shaped, black, hard gummy and long-stalked.

Twig: Mostly hairless, with 3-angled pith.

Bark: Brown; smooth becoming furrowed into broad plates.

Form: Straight trunk with rounded or oblong crown of dark green foliage.

Discussion: This introduced native ornamental tree is found in wet soils and humid, cool conditions. Can reach a height of 50-70' with a 1-2' trunk diameter.

Distribution: Introduced to U.S. and found throughout. Native of Europe, Asia and N. Africa. Naturalized locally in SE Canada and the NE U.S.

Images:

Typical Growth Form of Young Tree	Characteristic Leaf

Black Alder Reproductive Structures (Measured in Inches)

Mature Catkins(left) and Mature Cones (right)

Location:

Backyard, 803 E. Olympian Road, Urbana, IL, USA.

Copyright:

Spring, 2003 Organismal Biology Class and David M. Stone (Instructor), University Laboratory High School, Urbana, IL. Please contact dstone@uni.uiuc.edu for permission for use of these images. Permission will generally be granted for education- and non-profit-related use.

References:

More, David and John White, The Illustrated Encyclopedia of Trees, Timber Press, Portland, Oregon, 2002.

Petrides, George, A Field Guide to Eastern Trees, Peterson Field Guide Series, Houghton Mifflin Company, 1988.

National Audubon Society Field Guide to North American Trees: Eastern Region, Alfred A. Knopf. New York, 1996.

Trees of North America, Golden Press, New York, 1986.