Abies grandis

Grand fir (Abies grandis) is a shade tolerant, slow-growing evergreen tree with short, dense branches. It can get quite tall in the wild, reaching 250 feet in height and with a trunk diameter of up to 6 feet.

The glossy dark green leaves are needle-like, 3-6 cm long, and extend flat out from the branch on either side. The 6-12 cm cones do not fall to the ground whole, but disintegrate on the tree and release their seeds about 6 months after pollination.

Grand fir is an important wildlife tree. The California tortoiseshell butterfly feeds on the sap and secretions from cones and needles. Grouse eat the needles, and nuthatches, chickadees, and squirrels eat the seeds. Grand firs also provide excellent cover and nesting habitat for birds and small mammals.

The foliage has an attractive tangerine-like scent, and Grand Firs are sometimes used for Christmas decoration, including as Christmas trees. It is also planted as an ornamental tree in large parks.

Grand fir needs well-drained soils and plenty of room to grow, and is an elegant addition to any landscape.

Abies procera

Noble fir (Abies procera) is native to the Cascade Range and Coast Range mountains of northwest California, western Oregon and western Washington.

It is a large evergreen tree typically up to 40-70 m tall and 2 m trunk diameter (rarely to 89 m tall and 2.7 m diameter), with a narrow conic crown. The bark on young trees is smooth, grey, and with resin blisters, becoming red-brown, rough and fissured on old trees. The glaucous blue-green needle-like leaves are 1-3.5 cm long. They are arranged spirally on the shoot, but twisted slightly to curve up above the shoot. The cones are erect, 11-22 cm long; they do not fall to the ground intact, but instead ripen and disintegrate to release winged seeds in fall.

It is a high altitude tree, typically occurring at 300-1,500 m altitude, only rarely reaching tree line.

Uses

Noble Fir is a popular Christmas tree. The wood is used for general structural purposes and paper manufacture.

Acer macrophyllum

Acer macrophyllum (Bigleaf or Oregon Maple) is a large deciduous tree with the biggest leaves of any maple. It can grow to nearly 100 feet tall, but more commonly reaches 50-70 feet. It is native to western North America, mostly near the Pacific coast, from southernmost Alaska south to southern California. Some stands are also found inland in the foothills of the Sierra Nevada mountains of central California, and a tiny population occurs in central Idaho.

The palm-shaped leaves are typically 6-12 inches across, with five deeply-incised lobes. The flowers are produced in spring in loose dangling clusters, greenish-yellow with inconspicuous petals. The fruit is a paired, winged, V-shaped samara.

Bigleaf maple is a great wildlife tree. It provides nectar for pollinators, food for the young of tiger swallowtails and mourning cloak butterflies, and shelter for cavity-nesting birds. Mature trees are often covered with moss and ferns which are home to many invertebrates. These miniature ecosystems far above the forest floor capture and filter rain water, and provide food and nest material for birds and small mammals.

Cultivation and Uses

Maple syrup has been made from the sap of bigleaf maple trees. While the sugar concentration is about the same as in sugar maple (Acer saccharum), the flavor is somewhat different. Interest in commercially producing syrup from bigleaf maple sap has been limited.

The lumber from this tree has diverse uses, such as furniture, piano frames and salad bowls. Highly figured wood is not uncommon and is used for veneer and guitar bodies.

Alnus rhombifolia

Alnus rhombifolia is a medium-sized deciduous tree growing to 49-82 ft rarely to 115 ft tall, with pale gray bark, smooth on young trees, becoming scaly on old trees.

The flowers are produced in catkins. The male catkins are pendulous, yellowish, and produced in clusters of two to seven; pollination is in early spring, before the leaves emerge. The female catkins are ovoid, when mature in autumn and resemble a small conifer cone. The small winged seeds disperse through the winter, leaving the old woody, blackish ‘cones’ on the tree for up to a year after.

The White Alder is closely related to the Red Alder (Alnus rubra), differing in the leaf margins being flat, not curled under. Like other alders, it is able to fix nitrogen atmospheric nitrogen, and tolerates infertile soils.

If used domestically they should be planted well away from drainpipes, sewage pipes, and water lines, as the roots may well invade and clog the lines. These fast-growing trees often grow 3 ft. per year until 20 years of age. They are a relatively short lived species compared to other PNW native tree species.

Calocedrus decurrens

Incense cedar is a conifer native from central-western Oregon through most of California. It has a distinct symmetrical shape and can get up to 90 feet tall in its native habitat.

The bark is orange-brown weathering grayish, smooth at first, weathering to grayish, fissured bark that sheds in long strips on the lower trunk on old trees. The fragrant, bright-green foliage is produced in flattened sprays with scale-like leaves. The seed cones look like the open beak of a duck. They turn orange to yellow-brown when mature about 8 months after pollination.

Many birds depend on insects that live on incense cedar, including woodpeckers, brown creepers, red-breasted nuthatches, and golden-crowned kinglets. Birds use the dense foliage for nesting in the summer and shelter in the winter. This tree is also the preferred host of a wood wasp, Syntexis libocedrii, a living fossil species which lays its eggs in the smoldering wood immediately after a forest fire.

Cultivation and Uses

The wood is the primary material for wooden pencils, because it is soft and tends to sharpen easily without forming splinters. It is also a popular ornamental tree, valued for its drought tolerance. In cool summer climates (such as in Washington, British Columbia, etc.), incense cedar tends to grow narrower than in the wild, making it a good choice for large hedges and screens.

Fraxinus latifolia

Note: Due to the recent arrival of emerald ash borer in Oregon, ash trees in our region are at high risk of mortality over the next several decades. See OSU Extension Service’s emerald ash borer resources page for more information about how you can slow the spread and protect your ash trees.

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Oregon ash is native to western North America on the west side of the Cascade Range from southwestern British Columbia south through western Washington and western Oregon to central California.

It can grow to 80 ft in height, with a trunk diameter of 3ft. The leaves are pinnate, 3.5-10″ long, with 5-9 ovate leaflets. The fruit is a samara, 3-5 cm long including the wing. The leaves turn a striking yellow in the fall.

Oregon ash prefers damp, loose soils, and grows from sea level to 900 meters. It is a dominant tree in local forested wetlands, paired with an understory of spiraea and slough sedge.

Oregon ash is an ideal deciduous tree to plant along streams, seeps, and wet areas. It forms an attractive shape, tolerates saturated soils, and shades waterways.

Pinus ponderosa

Willamette Valley Ponderosa Pine (Pinus ponderosa var. benthamiana) is a beautiful tree with long needles and attractive bark. Like all ponderosas, the bark of this tree has a vanilla-like scent when warmed by the sun–and they love sunny spots! However, the Willamette Valley Ponderosa is the only variety of ponderosa that can also withstand the heavy wet winter soils of our region.

This long-lived tree is very valuable for wildlife. Its needles are the only known food for gelechiid moth (Chionodes retiniella) caterpillars. Many species of birds and small mammals eat the nutritious seeds and use the needles for nesting material; others use cavities and branches for nesting and shelter.

Willammette Valley Ponderosa Pine is one of four different varieties of Ponderosa Pine, each adapted to different climatic conditions and with differing botanical characteristics. When planting in Multnomah County, it is very important to use this variety, as it is the only one that will thrive in our region.

Populus trichocarpa

Balsam poplar (Populus balsamifera) is the northernmost American hardwood, and grows across the continent. Though it appears in upland areas, it thrives in floodplains. It is our tallest native broad-leaved tree, and has dark grey bark. In the spring and early summer the sticky resin on leaf buds releases a strong, balsamic fragrance. It is hardy, fast-growing, and relatively short-lived, though some trees have been known to live for 200 years. Other names are balm-of-gilead, bam, tacamahac, cottonwood, or heartleaf balsam poplar.

Wildlife

The leaves of the balsam poplar serve as food for various caterpillars in the order Lepidoptera. It is an important browse for deer and elk and provides nesting habitat for large birds. The anti-infectant property of the resin is used by bees, who seal intruders in it to prevent decay and protect the hive.

Uses

A great riparian restoration species. The light, soft wood is used for paper pulp and construction lumber.