Russian Olive trees are easily recognized by the thin, silvery leaves and thorns on the branches coming out next to the leaf stalks. The leaves have fine hairs which reduce moisture loss, an adaptation to allow it to be drought tolerant.
The bark turns from reddish-brown when young to smooth and gray, developing ridges and furrows with age.
This tree is generally 10-40 feet tall with a rounded crown and can be seen all over Denver as it was planted as a hardy ornamental tree.
Scientific Name and Plant Family information
The Scientific name for the Russian Olive tree is Elaeagnus angustifolia. Elaia is Greek for olive, and angustifolia means narrow leaves.
It is in the plant family Elaeagnaceae (Oleaster), which consists of thorny shrubs and trees which have silvery leaves. The color is due to the presence of minute hairs and scales on them that reflect the light.
Other plants in this family include silverberry and buffaloberry.
An interesting thing about plants in this family is that these plants do well in valley bottoms where the soil is dry, but where they have access to a water table.
Through the Seasons
In May-June, there are small yellow flowers that are strongly fragrant. The berries look like olives and are about 1/2 inch to 3/4 inch long.
Native or Non-Native?
The Russian Olive tree is not native. It was brought to this area as an ornamental plant, and it spreads easily through seeds and sending up suckers from the roots.
It has become a serious weed problem as it competes with native trees that provide better nesting and roosting for birds, and it uses more water than the native trees. It can be found throughout much of Colorado at elevations from 4,400 to 7,500 feet.
It is on List B of the Colorado Noxious Weed Act, which requires plans to be developed and implemented to stop the spread of these species.
Where to find in Willow Spring Open Space
Russian Olive trees are found along the bike path on the east side of the Willow Spring Open Space where there is a grouping of trees along a drainage ditch into the Open Space.
Did You Know?
The Russian Olive tree is not in the Olive family, but gets its name from its resemblance to Olive Trees in the Mediterranean.
- From Grassland to Glacier: The Natural History of Colorado and the Surrounding Region, by Cornelia Fleischer Mutel and John C. Emerick, 1992
- Botany in a Day: The Patterns Method of Plant Identification, by Thomas J. Elpel, 1967
- Flora of Colorado, by Jennifer Ackerfield, 2015
- Colorado Native Plant Database Data Portal, Colorado State University