Rocky Mountain Juniper trees are evergreen trees with gray-blue “berries”, which are actually cones with merged, fleshy scales.
The Rocky Mountain Juniper tree can grow to a height of 25 feet. It is often planted as a landscape plant and windbreak as it is adapted to low moisture and dry clay conditions .
In the Willow Spring Open Space, some Rocky Mountain Juniper trees are standing alone and have a nice regular shape to them (and probably have been planted there in the past), while others are part of a mixed cottonwood-juniper ecosystem.
The leaves (needles) are like scales, which help retain moisture. The bark is thin, reddish-brown to gray and is shredded. The cones, sometimes referred to as juniper berries, are blue-gray or purple fleshy scales with a waxy coating that is easily rubbed off.
Scientific Name and Plant Family Information
The Scientific name for the Rocky Mountain Juniper tree is Juniperus scopulorum. Scopulorum refers to cliffs or rocks, which are places where this tree can grow.
It is in the plant family Cupressaceae (Cypress), which also has the aromatic cedar trees, cypress and redwood and giant sequoia trees. This family of plants goes back to the Jurassic period!
A couple of interesting things about this family are that there are no flowers; the seeds are within cones (similar to the Pine family), and the evergreen leaves are small and scaly.
Through the Seasons
Since these are evergreen trees, they look about the same year-round. New growth at the tips of the branches may be a brighter green in spring and summer.
Native or Non-Native?
The Rocky Mountain Juniper tree is native to this area and grows well on dry slopes at elevations from 4,000 to 10,000 feet.
The Rocky Mountain Juniper pictured below is just north of the Englewood dam. It is next to some tall, mature Plains Cottonwood trees demonstrating a cottonwood-juniper climax (stable) ecosystem along Willow Creek.
Where to find in Willow Spring Open Space
Rocky Mountain Juniper trees that look like they have been purposefully planted can be found along the bike path on the west side of the open space. The more natural trees are near Willow Creek just north of the Englewood Dam .
Did You Know?
The berries are used for food by chipmunks and rock squirrels, and are also used to flavor gin!
References and Further Reading
- 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