Helena National Forest

Limber Pine (pinus flexilis)

Limber pine is a tree that lives on the edge. It may occur at the lowest elevations of forest growth, but it is also often found at higher elevations interfacing with prarie or grassland environments. The tree does display remarkable amplitude in where it may be found, but it is often found “on the edge.”

The tree is long lived and slow growing. It is small to medium sized. Some limber pines are over a thousand years old.

At lower elevations limber pine was exposed to frequent and low intensity fires. With its thin bark and low branches it would seem that the tree would be easily killed by fire, and it was where it grew in the grasslands. If you’re looking for an old monarch limber pine check the rock outcrops that were relatively flameproof.

Limber pine needles are in bundles of 5, which make it relatively easy to identify with one exception. Whitebark pine also has its needles in groups of 5. Because limber pine can occur at the same elevations as whitebark pine it is sometimes difficult to tell these two species apart.

The best way to tell the two trees apart is through their cones. During the growing season limber pine cones are green and oblong. Whitebark pine cones are purple and spherical. At other times of the year, if you see old cones laying on the ground you can be sure the tree is limber pine because a bird, the Clark’s nutcracker, tears the whitebark pine cones apart for their nutritious seed. You will never see an old whitebark pine cone.

The bark of the limber pine is grayish-brown. It is smooth on younger branches and more plate-like on older and larger stems.

Note the fire scar on this limber pine.

Limber pine does not have a value as a commercial forest product. Older trees sometimes develop cavities, which provide homes to birds and small mammals, and the tree can provide shelter from winds for other animals. Older trees are often twisted and gnarled and are quite beautiful, displaying the tenacity of life “on the edge.”