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.

Willamette Valley Ponderosa Pine

Ponderosa pine near Sisters, Oregon

Most of us in the Pacific Northwest are familiar with the ponderosa pine. Just the mention of it brings to mind its long needles and distinctive, golden bark. But where do you picture these pines growing? Most likely it’s east of the Cascade Mountains, perhaps around Bend. So, it might surprise you to find out that ponderosa pine is also native to Oregon’s Willamette Valley. The ponderosas of the Willamette Valley are adapted to the wet conditions found west of the Cascade Mountains. Even more surprising, these natives are better adapted to wet areas than the Douglas firs that grow in the valley. I remember that we had two large ponderosas growing in a particularly wet area on the farm where I grew up northwest of Eugene. Although I didn’t know a ponderosa from a pond-lily at the time, I remember the distinctive look of these trees.

Willamette Valley ponderosa
at Tualatin Hills Nature Park

The ponderosa pines that grow west of the Cascades and on the west slopes of the Sierras in California have been classified as a separate subspecies, sometimes called “Pacific ponderosa pine” (scientific name: Pinus ponderosa subspecies benthamiana). Those that have adapted to the wet conditions of the Willamette Valley are often called “Willamette Valley ponderosa pine.” Studies of ancient pollen show that these pines have been present in the Willamette Valley for over 7,000 years.

Willamette Valley ponderosa pines have long needles growing in bundles of three, like other varieties of ponderosa pine. The bark and cones also look similar. The needles and cones of the subspecies are a little shorter, and the bark is not as thick, but none of these differences are definitive. The key difference is that Willamette Valley can thrive in wet locations in the Willamette Valley. That alone indicates that they are clearly genetically different from the other trees of the benthamiana subspecies. Some have suggested giving them official status as a separate variety, with the name Pinus ponderosa variety willamettensis.  

Before European settlement in the 1850’s, ponderosas grew in scattered locations all over the Willamette Valley, mostly in wet, boggy areas along with ash, and on hillsides with white oak or Douglas fir. Like the ponderosas east of the Cascade Mountains, the Willamette Valley natives depend on frequent fires to eliminate competing conifers. These naturally occurring fires would burn up the grasses, shrubs and other competing conifers like Douglas fir and grand fir. But the thick bark on the ponderosas enabled them to survive these fires. The earliest inhabitants of the Willamette Valley understood this and used it to their advantage, setting fires to clear brush and other conifers. This maintained open ponderosa woodlands good for hunting. The European settlement of the Willamette Valley changed all that. These newcomers cut down the trees for lumber and other uses, turning the woodlands in the valley into farmland.   A sawmill was built in 1853 at Monroe, south of Corvallis, where there was a good supply of ponderosa pine. Sustainable forestry wasn’t a thing at that time. Soon all the nearby pines were cut down, and the mill closed. It wasn’t long before there were few ponderosas growing anywhere in the Willamette Valley. 

Willamette Valley pines
at the Oregon Garden

Recently, researchers wanted to see if they could restore ponderosas to the Willamette Valley. Plantings of east-side and west-side ponderosas on a test site near Corvallis determined that the east-side trees did not grow well in this wet environment. Any successful restoration would have to use seeds of ponderosas native to the valley. In the 1990’s researchers began collecting seeds from various Willamette Valley locations and growing trees in a seed orchard near St. Paul, Oregon. The seed orchard has provided seeds for restoration and planting in parks and other locations where the trees can thrive. Not much restoration has been done, but you can now find them here and there in parks.

The best location I’ve found for mature Willamette Valley ponderosa pines is the Tualatin Hills Nature Park in Beaverton. There are large ponderosas scattered here and there all over the park. Just look for the long needles on the trail and then look up. You’ll likely see a large ponderosa. 

Pine-Oak woods at the Oregon Garden

Willamette Valley ponderosa pines have been planted in many other parks in the Portland area. For example, Cooper Mountain Nature Park and the Tualatin River National Wildlife Refuge have plantings of Willamette Valley natives. 

The Rediscovery Forest at the Oregon Garden in Silverton has a section of Willamette Valley ponderosa pine. These were planted in neat rows in 2002. For comparison, some east-side ponderosas are planted next to them. Nearby, more ponderosas were planted with Oregon white oak, showing how these trees grew together 150 years ago forming a pine-oak savannah. 

Locations of Willamette Valley Ponderosa from Oregon Flora

Ponderosa at Hagg Lake

On a recent hike at Henry Hagg Lake south of Forest Grove, I was surprised to see a few ponderosas growing along the trail. Keep your eyes open when you are hiking on local trails in the Willamette Valley. You may see a Willamette Valley ponderosa pine. If the bark doesn’t have the bright colors of the ponderosas east of the Cascades, be patient. This only appears on very old trees. Enjoy these stately trees as they grow older. You may see the brightly colored bark in about 75 years.

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More info

Rediscovery Forest Pine Demonstration Area at Oregon Gardens

Willamette Valley Ponderosa Pine Association

Oregon Flora

Ponderosa pines at the Gymnosperm Database

Conifers in Spring

Douglas fir

What are conifers doing in spring?  Why is it that no one notices? Well, I suspect that it is because there is too much competition from more glamorous plants like tulips and trilliums. Not even the humming birds and bees seem to pay any attention to the conifers, not that we should blame them. The conifers don’t advertise and don’t offer any nectar. Apart from the stiff competition from flowering plants, why is it that we don’t notice the growth changes of conifers in spring? I think there are primarily two reasons. One reason is that most conifers are evergreen. When deciduous trees put out new leaves the change is transformative. You can’t help but notice the difference between the naked winter branches and the burst of bright green leaves.
Conifers do put out new leaves in spring, but it’s just a little bit more of the same. You might notice that the new needles on a fir are a little brighter than the old ones, but you would be excused if you didn’t notice any difference at all. The other reason is that the “flowers” that grow on conifers are often very small. You might be looking at a branch at arm’s length and not even see them.

Grand fir

The needles on conifers don’t last forever. To maintain their status as an evergreen, the needles only have to last over a year. Most last for several years. But they generate new needles every year. You can see the buds in early spring. Each bud contains a bundle of needles. At budburst, the needles pop out in this bundle. In many conifers, the needles remain in this bundle. In others, the needles are distributed along the twig as it grows. However, not all conifers are evergreen. Some lose their needles in the fall, like most flowering trees. For example, the larches are bare all winter and burst out in a glorious display of bright green needles in the spring.

Western hemlock

Western red cedar

Most conifers develop buds during the winter. Western red cedar is an exception. New leaves just start growing at the leaf tips.

Western hemlock cones and pollen cones

The defining characteristic of conifers is that they produce cones. It is noteworthy the conifers produce two kinds of cones: The female seed cones and the male pollen cones. We are familiar with the seed cones. Some of them are quite large. However, the pollen cones are often tiny, some of them the size of a pea, some much smaller.

Western red cedar cones and pollen cones

Most conifers produce seed cones and pollen cones on the same tree. It’s no surprise that this presents a problem for the offspring, just as interbreeding does for other organisms. Conifers have developed several strategies for avoiding self-pollination, for example, growing seed cones at the top of the tree and pollen cones in the lower branches, or having pollen cones that mature at a different time from the seed cones.

Pacific silver fir pollen cones before and after pollen release

Many conifers produce pollen cones when they are young and seed cones when they are older. A few conifers, for example, all of the yews, take a more radical approach: They produce seed cones and pollen cones on separate trees, making self-pollination impossible.

Port Orford cedar cones

Even though seed cones can be quite large, in spring when pollination happens, they are quite small, sometimes no larger than the pollen cones.  As they grow, early on they develop hard woody scales that protect the seeds inside. On the other hand, pollen cones are quite delicate. They only have to last long enough to generate the pollen, which is contained in tiny sacs. When the pollen cones are mature, these sacs burst open and release the pollen.

Ponderosa pine pollen cones

Pollen in other trees is distributed mostly by insects. This explains all those colorful flower advertisements that plants create to attract the insects. Humming birds are attracted to the flowers, too. Since conifers don’t produce flowers, how does the pollen get distributed to the seed cones? The answer is wind. When the pollen cones release the pollen, the wind carries it to the seed cones. As you can imagine, this isn’t an efficient way to manage pollination. Most of the pollen never makes its way to a seed cone. This is why conifers distribute copious amounts of pollen. You can often see clouds of yellow pollen drifting from pine trees on a windy spring day. You may also see a small cloud of pollen if you reach up and tap a cluster of mature pollen cones.



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See also
Conifer Pollination
Pollen Allergies

The White Pines

The Pinus genus has more species than any other genus of conifers, by one count 114, and by any calculation, too many to keep track of. So it’s no surprise that taxonomists have divided the pines into two subgenera. One group, subgenus Pinus, is typically called the hard pines. Natives of the Pacific Northwest in this group include lodgepole pine, ponderosa pine, and Jeffrey pine. The other group, subgenus Strobus, is called the soft pines or white pines. The white pines of the Northwest include western white pine, whitebark pine, sugar pine, and limber pine. Since all of the white pines have needles that grow in bundles of five, they are also called five-needle pines. This is a good thing to remember, because it is how you can distinguish them from the other native pines, which have two or three needles per bundle.

Western white pine

What is the difference between hard pines and soft pines? These descriptions refer to the wood. We usually think of hard woods as the wood from flowering trees, for example, oaks and maples. However, some conifers produce relatively harder woods than others. Fir and hemlock wood is fairly soft. The wood of white pine is moderately soft. White pine has been used for construction, although much of the white pine forests of North America have been cut down. Eastern white pine was once the preferred tree for the masts of sailing ships in the British Navy. In fact, the British went around marking suitable white pines for the exclusive use of the King. Unmarked white pines were put to other uses, including house construction. The light color and moderate softness of white pine make it a good choice for window frames and other finish lumber. It is easy to carve, mill or sand, and retains its shape. Whether painted or stained, it finishes well.

Western white pine (Pinus monticola) is the most common native white pine of the Pacific Northwest. It can grow to over 200 feet tall and has cones that are larger than eastern white pine (Pinus strobus). Both trees have cones with a characteristic banana shape, but those of western white pine are also about the size of a banana. However, the sugar pine (Pinus lambertiana) is the granddaddy of the white pines. In fact, it is the tallest of all the pines. The tallest sugar pine is in Yosemite National Park and is over 270 feet tall. Just as notable, the sugar pine has the longest cones of all the conifers, up to 19 inches long. 

Sugar pine

If you frequent the higher elevations of the Cascades, you will meet another, very different white pine. The whitebark pine (Pinus albicaulis) that grows here is not large in stature, but these pines are a very important food source for some very important birds, if the amount of noise the birds make is any measure of their importance. These birds are the Clark’s nutcracker and the Steller’s Jay. The cones of other native white pines open and distribute their winged seeds when they mature. Not so with whitebark pine. These cones remain closed on the tree until a nutcracker or jay comes along to pry the cone open and extract the seeds. They eat the seeds or hide them to eat later. The relationship between whitebark pine and the Clark’s nutcracker is such a close one that whenever you hear a Clark’s nutcracker, you can be sure that whitebark pine is nearby. This relationship between the two is a symbiotic one. The nutcrackers get some food. The pines benefit by getting the birds to distribute their seeds to places where they can germinate. No doubt, this is not the intention of the birds, but they don’t remember where they “planted” all those seeds, despite the fact that researchers extol their memory capabilities. Not even a genius can remember everything. That is why whitebark pine has spread all over the cascades. Either that or the nutcrackers just hide more whitebark pine seeds than they can eat.  

Whitebark pine

Similar species of white pines grow all over the Northern Hemisphere. Mexican white pine (Pinus ayacahuite) is closely related to eastern white pine. Other species, called the stone pines, have large edible seeds like the whitebark pine, including Italian stone pine (Pinus pinea) and Swiss stone pine (Pinus cembra). Those expensive pine nuts you see in the grocery store may have come from these European species, but more likely they are Korean pine (Pinus koraiensis).

White pine blister rust is a disease caused by an Asian fungus species, which was introduced to North America over 100 years ago. It has caused serious damage to the white pines all across the U. S. In the Northwest, white pine blister rust has infected large areas of whitebark pine. Efforts are now underway to develop genetic strains that are resistant to the disease. More information.