Limber Pine, Pinus flexilis

Limber Pine (Pinus flexilis) grows in the sub-alpine mountainous regions of the Western United States, Mexico, and Canada, with a small cropping found in the Black Hills in South Dakota. One of the oldest trees to be documented is found in Eagle Cap Wilderness in Oregon and is reported to be 2000 years old. This pine is also known as the Southwestern White Pine and Rocky Mountain White Pine.

The Limber pine is drought tolerant and grows at high elevations (5000-12,000 feet) marking the sub-alpine region. This pine is relatively short growing from 16 – 33 feet high with some growing to 66 feet in perfect growing conditions.  Limber pine found growing on the rocky slopes in southern Alberta are less than 10 feet tall.

Limber pine branches are light to dark greenish gray with the old trunks aging to a dark gray or dark brown. The bark is separated by deep grooves causing rectangular plates to form. The crown of the limber pine can spread from 10 – 15 feet. The needles grow in bundles of five, smooth to the touch, dark green-bluish in color, and measures up to 3.5 inches long. The cones are green when immature and mature to brown cones that measure up to 8 inches long and has thick scales, which protects the seeds when the cone falls to the ground.

The most prevalent disease to threaten the Limber pine is the white pine blister rust. This disease has killed many trees throughout its range with no hope of preventing the disease from spreading.
The Limber pine is grown as a windbreak, as ornamental trees, or as a Christmas tree. The Limber pine serves as a nesting tree for squirrels, Mourning Doves, Northern flickers, and mountain bluebirds. The red squirrel and Clark’s nutcrackers as well as the American black bear like the pine nuts.

Image Caption: Limber Pine (Pinus flexilis). Credit: Famartin/Wikipedia (CC BY-SA 3.0)