Conifers By Genus

Many people who love nature and hiking in the woods of the Pacific Northwest like to identify the individual species of the flowers, birds, trees, and other plants and wildlife they see there. However, learning all these names can be a taxing task that requires time and a backpack full of nature books. Someone asked me recently to identify not a particular species, but just how to identify a tree as a fir. This seems like a good way to start learning the conifers. So here is an overview of the conifers of the Northwest that can help you ID each genus.

Firs – Abies

The cones of the firs are perched on the top of the upper branches, and fall apart at maturity when they disperse their seeds. So you seldom see any fir cones lying under the trees. Look for the cones in the tree tops in the summer. The bark is smooth with resin blisters on younger stems and has furrows between smooth plates on larger trunks. The needles have an orderly, groomed look, usually flattened or curved upwards.  All the needle tips of Northwest firs are soft and not prickly. Finally, when the needles fall off, they leave round, flat scars on the twig. Abies is the scientific name of the genus, from the Latin abeo, which means "to rise."

Douglas fir – Pseudotsuga

Now, what about Douglas fir? It is very different from the firs described above, and its unique features make it easy to identify. The thin needles stick out in all directions from the twig like a bottle brush. Although their appearance is similar to that of spruce needles, the Douglas fir needle tips are soft, unlike the sharp spruce needles. Finally, look at the buds if there are any. Douglas fir has unique buds that are long and pointed, unlike the short, rounded buds on the true firs.

Douglas fir cones are the only ones you will find in the Northwest with three-pointed bracts sticking out of the scales.  Unlike the true firs, the cones hang down rather than standing up on the branch. Also unlike the true firs, the Douglas fir drops its cones to the ground intact. When you see these unique cones on the ground, you know that you are standing near to a Douglas fir.  You can usually identify a large Douglas fir by the bark alone. On large trees, the thick bark is deeply furrowed, more than any other tree in the region. The color is gray to brown and usually brown at the bottom of the furrows. The scientific name, Pseudotsuga, tells you that the Douglas fir is in a different genus from the Abies genus of the firs. Pseudotsuga means “false hemlock.”

Hemlocks – Tsuga

Western hemlock

The Northwest has two species of Hemlock. It is easy to distinguish them from other native conifers by their short, flat needles and by the drooping leaders at the top of each tree. The cones have rounded scales like Douglas fir, but don't have bracts protruding from them. The scientific name, Tsuga, is the Japanese word for hemlock tree.

Pines – Pinus

Although pines are the most common conifer throughout the world, they don't compete as well in the climate of western Oregon and Washington where forests are dark, damp, and dense. You will find them high in the mountains in more open forests and east of the Cascades summit where the weather is dry. Pines have long needles that grow in bundles of two to five. The cones are the largest you will find in the Northwest. Unlike the thin scales on hemlock and spruce cones, pine cones have thick, woody scales. Pinus, of course, means "pine tree."

Spruces – Picea

The Spruces are easy to identify. The needles look like Douglas fir needles, but the points are sharp. Also, each spruce needle grows on a small peg. These unique pegs remain even after a branch loses its needles. The cones have paper-thin scales that tend to come to a point. The bracts are not visible. The bark is gray and breaks into small scales on large trees. Picea is derived from the Latin for "pitch."

Larches – Larix

Unlike most conifers, larches are deciduous, dropping their needles in the fall. The needles grow in bundles like the pines, and have about 25 needles per bundle. The needles usually grow on a distinctive little spur twig. Larix, translates from Latin to "larch."

Cedars

The cedars of North America are very different from the "true cedars" (genus cedrus) of the Himalayas and the Mediterranean region. These cedars and all of our native conifers above belong to the pine family. All our native cedars belong to the cypress family. They are easy to distinguish from other native conifers because they all have flat, scale-like leaves, unlike the needles found on other conifers.

Yews - Taxus

Pacific Yew (Taxus brevifolia) is our only native species of the yew family. Pacific yews have short, flat, needles that spread out on opposite sides of the twig in flattened rows. They are dark green on top and lighter green below. The needles are about 1 inch long, but become shorter near the tip of branchlets. Pacific Yew bark is smooth and purple or red-brown. It is often covered by a peeling, papery gray or brown layer.

Families

If you find identifying each native genus too daunting, you can always fall back to just identifying the families. There are only three families of conifers native to North America:

• The yew family – trees with needles and smooth, purple bark.
• The pine family – other trees with needles.
• The cypress family – cedars with flat leaves and junipers with awl-shaped leaves.

For information on the individual species, see Overview at Northwest Conifers.