Keys to Identification
- Tree or shrub up to 30 ft tall
- Leaf is light green above and silvery beneath
- Many yellowish olive-shaped fruit
This information courtesy of the Colorado Natural Areas Program
Colorado Noxious Weed List B
Small, light yellow clusters, bisexual.
Olive-shaped fruits, silver when first formed becoming yellow-red when mature. Produced in 3 to 5 years, in great quantities.
Simple, alternate, narrow 2 to 3 in long, and are untoothed. The upper surface of the leaf is light green, the lower surface is silvery white with dense scales.
To 30 ft tall, trunks and branches have 1 to 2 in long thorns.
Can reproduce by seed or root suckers. Tolerant of shade
Invades both upland and riparian communities. Creates monotypic stands which replaces native vegetation, altering structure nutrient cycling, and system hydrology.
Habitat and Distribution
Can grow in a variety of soil and moisture conditions, but prefers open, moist riparian zones.
Primarly found in central and western U.S. but is also found in eastern U.S.
Introduced from Europe.
Whitson, T.D.(ed.), L.C. Burrill, S.A. Dewey, D.W. Cudney, B.E. Nelson, R.D. Lee, R. Parker. 5th Edition 1999. Weeds of the West.
Western Society of Weed Science, in cooperation with the Western United States Land Grant Universities Cooperative Extension Services, Newark, CA
Hickman, J.C. (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley.