Trees to know in Central Oregon

Feb 01, 2016
Central Oregon has a diverse array of native trees and shrubs. Here are a few common ones found at Land Trust protected lands.

Ponderosa pine. Photo: Bob Woodward.
Ponderosa pine. Photo: Bob Woodward.
Ponderosa Pine (Pinus ponderosa)

Evergreen. Large pine (often 60-130’ tall) of dry forest lands.

  • Needles 4-10” long in bunches of 3.
  • Cones 3-6” by 2-3” with stout re-curved barbs
  • Bark of young trees very dark brown, but will soon furrow and mature to yellowish and reddish brown, breaking into plates and scales shaped like jigsaw puzzle pieces. Mature ponderosas are very fire-resistant thanks to high crowns and thick bark.

Search for more photos of Ponderosa pine (Pinus ponderosa) on Oregon Flora Project.

 


Western White Pine (Pinus monticola)

Evergreen. Tall, often to 100’. Distinguished from other pines by tall, narrow form, dense clusters of bluish-green needles, and slender, hanging cones.

  • Needles blue-green, in bundles of 5, 2-4” long; white lines on two sides of each three-sided needle
  • Cones are woody, 5-12” long, slender and curved. Cone scales are thin and often curve up on the end.
  • Bark is dark, broken into small squares or rectangular blocks on older trees. Bark is often ringed where a whorl of branches once grew.

Search for photos of Western white pine (Pinus monticola) on Oregon Flora Project.


Western larch. Photo: Byron Dudley.
Western larch. Photo: Byron Dudley.
Western Larch (Larix occidentalis)
Deciduous. Tall slender tree, often over 100’. Straight trunk with short branches only near top, creating unusually short, narrow crown. The only deciduous conifer, i.e. needles fall from the tree in winter. Needles are soft, pale green in spring and an intense yellow in the fall.

  • Needles about 1” long growing in dense clusters attached to short woody shoots. Needles are soft to the touch, never sharp or spiny.
  • Cones are small (1-2”) and held upright directly along branchlets.
  • Bark is reddish-brown, scaly, with deep furrows between flat cinnamon colored plates.


Search for more photos of Western larch (Larix occidentalis) on Oregon Flora Project.

 


Douglas Fir (Pseudotsuga menziesii)
Evergreen. Most abundant tree species in Oregon and the conifer with the greatest north-south range (from northern B.C. to Mexico). It has at various times been called a pine, a spruce, a hemlock and a true fir, but it is a member of its own genus Pseudotsuga, which means false hemlock.

  • Needles single ½-1-1/2” long generally with white stripe on underside, blunt-tipped (not sharp to the touch).
  • Cones 3-4” long with a paper-thin 3-pointed bract sticking out beneath each woody scale. These bracts have been compared to a three-pronged pitchfork and to the hind feet and tail of a mouse diving into a hole.
  • Bark of mature trees dark brown and deeply grooved.


Search for photos of Douglas fir (Pseudotsuga menziesii) on Oregon Flora Project.

 

Grand fir. Photo: Land Trust.
Grand fir. Photo: Land Trust.
Grand Fir (Abies grandis)
Evergreen. A true fir. True firs, (Genus Abies) are so named to distinguish them from Douglas-firs and a number of other “pretenders”. Medium to large trees, often 150-200’ tall. Trees tend to have narrow shape and rigid upright or horizontal branching.

  • Needles are about 1” long and highly aromatic. Blunt to the touch. Yellowish-green on top surface, white bands on underside. Needles are two distinct lengths, alternating longer and shorter.
  • Cones are upright, cylindrical, 3-4”, perched on the topmost branches. Cones of true firs do not fall intact like other conifer cones. In late fall, their scales tumble off one by one when the seeds have ripened.
  • Bark is smooth and pale gray, becoming thicker on older trees and dividing into thick, flat-topped ridges.


Search for photos of Grand fir (Abies grandis) on Oregon Flora Project.

 

Juniper. Photo: Brian Ouimette.
Juniper. Photo: Brian Ouimette.
Western Juniper (Juniperus occidentalis)
Evergreen, dense small conical trees 25-40’ tall, limbs nearly to the ground. Dry country species.

  • Leaves in whorls of three, each whorl rotated 60 degrees from the next. Mature leaves tiny, scale-like, yellowish green, tightly encasing the twig.
  • Bark red-brown, fibrous, shredding, becoming furrowed.
  • Fruits are leathery and look like small, hard blue berries.

 

Search for photos of Western juniper (Juniperus occidentalis) on Oregon Flora Project.

 

Aspen. Photo: Byron Dudley.
Aspen. Photo: Byron Dudley.
Quaking Aspen (Populus tremuloides)
Deciduous, small tree growing 40-80’ tall. Slender main trunk.

  • Leaves 2-3” heart-shaped to round, green above and paler below. Fall color is yellow to gold.
  • Bark greenish white, smooth when young, but dark and furrowed on old trees or where it has been chewed.
  • Cool fact: Aspen are the widest ranging American tree, growing from Alaska to New England and down to the Rockies and Sierra Madres into Mexico. Almost 200 species of birds and mammals use aspen. Aspen are fire-adapted! While all the trunks may die in a fire, the roots survive all but the most intense fires, sending up shoots. Entire groves are clones--genetic individuals of just one sex with interconnecting root systems. The largest clone known, in Utah, covers 106 acres! The oldest is estimated to be 80,000 years old, possibly the oldest living thing on earth.


Search for photos of Quaking aspen (Populus tremuloides) on Oregon Flora Project.

 

Black Cottonwood (Populus trichocarpa)
Deciduous medium to large tree often 60-90’ tall. Largest broad-leaved tree in the West.

  • Leaves triangular 3-6”; green above and white below.
  • Bark smooth and gray on young trees, furrowed and ridged on mature trees.
    Often grows along streams.


Search for photos of Black cottonwood (Populus trichocarpa) on Oregon Flora Project.

 

Mountain Alder (Alnus incana)
Deciduous. Small tree or shrub, usually under 20’, along streams. Often multi-trunked.

  • Leaves alternate, egg-shaped leaves with serrated or doubly serrated margins.
  • Cones small and woody, about 1” long. Distinctive cones hang from the tree throughout the winter.
  • Bark on young alders is shiny brown with white horizontal markings (lenticels). Older shrubs have grey bark with many horizontal lenticels.
    Commonly found in moist areas next to water.
  • Cool fact: Alders host bacteria in nodules on its roots that convert atmospheric nitrogen for plant use, fixing some in the soil and some directly into the plant. Decomposing alder leaves improve soil structure by adding nitrogen.


 Search for photos of Mountain alder (Alnus incana) on Oregon Flora Project.