This is a blog about the native conifers of the Pacific Northwest. It is a companion to the Northwest Conifers site. The blog will focus on timely and interesting details about our conifers, their connections to the rest of the environment, and our connection to them.

Thursday, October 22, 2020

Douglas Squirrel

Walking in the conifer forests of the Pacific Northwest is always a visual feast, with so many tall, awe-inspiring trees and an enchanting understory of diverse shrubs and wildflowers. However, you will miss a wonderful part of the experience unless you are quiet and listen. You can hear a chorus of various bird calls and songs. However, one of the most intriguing calls is not from a bird at all. It is the melodic call of the Douglas squirrel.

The most frequent Douglas squirrel call is similar to the call of a flicker. It is a short burst of high frequency that quickly drops in frequency and volume: “Chee-you.” This call is a warning that a predator is nearby. Maybe the squirrel has spotted you. When really excited, it gives a rapid sequence of just “chee chee chee chee” sounds. The other sound you will often hear is a long, continuous “cheecheecheecheechee.” This is the Douglas squirrel’s intruder alert. These squirrels are territorial and will defend the area around their nest and food cache. Perhaps it doesn’t have a large vocabulary, but this string of loud squirrel profanity would give any intruder pause. If you surprise a Douglas squirrel on the ground, it may make an excited combination of variable sounds as it scampers up a tree. You can hear the different sounds here

Other sounds to listen for: The scurrying of little squirrel feet scampering up a tree trunk. Also, if you hear the sound of cones hitting the ground, chances are, there is a Douglas squirrel dropping them from the top of a nearby tree.

The Douglas squirrel is a small squirrel native to the conifer forests of the Pacific Northwest. In summer, it is brown on top and orange underneath with a dark stripe on the side between the top and bottom colors. In winter, the top is darker, and the color below turns light gray. The dark stripe on the side fades in winter. The Douglas squirrel is about 12 inches long, including its bushy tail, much smaller than the western gray squirrel, and somewhat smaller than the two non-native squirrels often seen in urban areas: the eastern gray squirrel and the fox squirrel.

What the Douglas squirrel lacks in size, it makes up in energy and personality. It races up and down trees, takes flying leaps from branch to branch and tree to tree. Even when it is still, it appears and sounds like a concentration of suppressed energy, calling and flicking its tail. It is these birdlike calls that distinguishes the Douglas squirrel from the larger squirrels. Their calls sound like the unremarkable bark of a tiny dog.

The favorite game of the Douglas squirrel is the chase. Juveniles start playing this game as soon as they can be out of the nest, chasing each other up, down and around tree trunks, leaping from branch to branch. It is good training for the adult chase, which takes two forms. One is the intruder chase, which starts when an intruder ignores the loud intruder call. The other is when a female leads a male on a mating chase.

The Douglas squirrel was a favorite of John Muir. He devoted an entire chapter to this squirrel in “The Mountains of California.” He wrote that the Douglas squirrel

… threads the tasseled branches of the pines, stirring their needles like a rustling breeze; now shooting across openings in arrowy lines; now launching in curves, glinting deftly from side to side in sudden zigzags, and swirling in giddy loops and spirals around the knotty trunks; getting into what seem to be the most impossible situations without sense of danger; now on his haunches, now on his head; yet ever graceful, and punctuating his most irrepressible outbursts of energy with little dots and dashes of perfect repose. He is, without exception, the wildest animal I ever saw….

Douglas squirrels like mature forests with cone bearing conifers. The seeds inside the cones are their primary food. A squirrel will get a cone, sit on a branch, deftly strip the scales, and eat the seeds inside. In about two minutes, the squirrel will be finished and drop the stripped cone core. The squirrels often have a favorite spot for stripping cones, creating a large mound or midden of cone scales below. Look for the tiny “cone cobs” in the midden.

A squirrel strips a cone, asks, "You looking at me?" And is off in a streak.

Douglas squirrels also eat fungi, and the seeds from maples and other broadleaf trees. In the spring they feast on the tender new growth from a great number of trees, including flowers, pollen cones, and conifer needles.

Douglas squirrels do not hibernate. They must store food for winter. When they drop cones on the ground, they will come down and carry them off to a hidden cache, usually under a log or some other damp place. They do this in late summer or fall after the cones are mature, but before they open and disperse the seeds. Timing is critical. They must wait until the seeds inside are fully developed. And storing cones with no seeds is, well, just pointless.

The scientific name of the Douglas squirrel is Tamiasciurus douglasii, both named after David Douglas. It is native to the forests of western Washington and Oregon. It also lives in southwest British Columbia and northern California. Its cousin, the American red squirrel (Tamiasciurus hudsonicus) is widely distributed across the rest of North America wherever conifer forests grow, including eastern Washington and northeast Oregon. Both species are sometimes called pine squirrels or chickarees. Although the range of the two species does not overlap, curiously, the red squirrel lives on Vancouver Island, while the Douglas squirrel populates the coast of mainland British Columbia.

Be sure to listen for these squirrels when you are hiking in the woods. If you hear one high in a tree overhead, sit down and wait. It may come down for a closer look, and possibly give you a sharp burst of squirrel profanity for invading its space.


More info

Sunday, October 4, 2020

Focus on Whitebark Pine

Whitebark pine is a perfectly adapted alpine tree. It grows at or near the timberline throughout the mountains of the Pacific Northwest. Since it doesn’t compete well with other conifers in wet or shady locations or on north facing slopes, you will find it in open, dry and sunny locations on ridgetops or south facing slopes.  Whitebark pine is the only stone pine that grows in North America. The stone pines have large wingless seeds. Other stone pines grow in Europe, China and Korea. These edible seeds are called “pine nuts,” which you can buy in grocery stores if you can afford them.

You can identify whitebark pine by counting the number of needles in each bundle. Whitebark pine needles grow in bundles of five. Western white pine also has 5 needles per bundle, so it’s easy to confuse it with whitebark pine. However, if you see any cones, and can tell eggs from bananas, it’s easy to tell them apart. Whitebark cones are about the size and shape of eggs, while western white pine cones are about the size and shape of bananas.

The most remarkable thing about Whitebark pine is its relationship to the Clark’s nutcracker. Unlike the cones of most other native pines in the Northwest, which open and disperse their winged seeds, white bark pine cones remain on the tree and do not open when they mature. This is where the eating habits of the Clark's nutcracker play an essential role in the life cycle of the Whitebark pine. These birds easily pull apart the cones to get the seeds and bury them in the ground for eating later. Or perhaps they fancy themselves as tree planters. It’s just that they often get hungry and return to eat some of the seeds. In either case, they don’t eat all of the seeds they “plant,” so some of them germinate and continue the life cycle of the pines. This paradigm case of mutualism benefits both the nutcrackers and the whitebark pines. However, nutcrackers don’t get all of the whitebark seeds. They are also a favorite of Steller’s jays, Douglas squirrels, golden-mantled squirrels and chipmunks.

By the way, the feeding habit of nutcrackers is why you seldom find any whitebark pine cones on the ground, just cone fragments left by the nutcrackers. This can make it more difficult to tell a whitebark pine from a western white pine. If you are at the timberline, it’s probably a whitebark. If it’s a small tree, it may not be producing cones yet, so good luck. Looking at the needles may help. Whitebark needles are green, while western white pine needles are blue-green.

The scientific name of whitebark pine is Pinus albicaulis. The common and scientific names describe the whitebark pine. Albicaulis means "white stemmed." To remember the name, think of it as the "Albino-bark Pine." Other common names: Pitch pine, scrub pine, and creeping pine. John Muir called it "Dwarf Pine."

If you go looking for whitebark pine, you may be disappointed. Like other white pines, whitebark pine has been decimated by white pine blister rust. You can see their ghostly, white forms still standing in large areas, for example, above Mount Hood Meadows. White pine blister rust is a disease caused by an Asian fungus, 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. The fungus first attacks the needle, then the branches, and eventually the trunk of the tree.

Whitebark pines tested for resistance to blister rust.
Some survive, others, not so much.

White pine blister rust has a fascinating life history. It requires two host species to complete its life cycle. One is a white pine. The other can be a variety of plants from the Ribes genus, locally, usually shrubs like currants and gooseberries. The infected shrubs infect the trees, and the trees in turn infect more shrubs. If you remove one of the hosts, the fungus cannot reproduce. Years ago, the Forest Service sent out summer workers to clear affected areas of the shrubs necessary to complete the life cycle of the fungus. Unsurprisingly, that effort failed. More recently, efforts have been underway to develop genetic strains of whitebark pine that are resistant to the disease. For details on this effort, see this post on the Dorena Genetic Resource Center

Whitebark pines just don’t seem to be able to catch a break. Recently, the mountain pine beetle has attacked large areas of whitebark pine. More outbreaks are likely as winters become warmer allowing pine beetles to survive in areas where they were once killed by cold winters. Due to the decline in whitebark pine from blister rust and beetles, it is now listed as an endangered species on the IUCN Red List. Climate change may prove to be the biggest challenge to the survival of whitebark pine.

Whitebark pines may need our help to survive the assault of these enemies. They are an important member of the alpine ecosystem, providing food for nutcrackers and shelter to other birds and mammals, and contributing to the beauty of the high mountain environment. We can help them survive by supporting efforts to combat blister rust, and by reducing greenhouse gas emissions.

If you want to see some whitebark pines, here are some locations that are easy to get to: Above Timberline Lodge on Mount Hood, on the rim above Crater Lake, and at the top of the Mount Howard tram at Wallowa Lake.


More info

Northwest Conifers: Whitebark Pine  

Gymnosperm Database: Pinus albicaulis 

Our Threatened Timberlines: The Plight of Whitebark Pine Ecosystems  

Sunday, September 20, 2020

Focus on Western White Pine

Western white pine doesn’t have the charm and stature of ponderosa pine with its golden bark and lofty height, but this white pine does have many subtle, attractive qualities. It grows straight and tall when given a chance, sometimes to a height of nearly 200 feet. The needles grow in bundles of five and have a blue-green color. The cones have a distinctive banana shape and are longer than any other Northwestern conifer except sugar pine cones. The gray bark breaks into rectangular plates on large trees. Another distinctive feature is the sticky resin on the cone scales. You will often see cones on the ground under a western white pine, and if you pick one up, don’t be surprised if you have sticky fingers. You were warned.

The scientific name of western white pine is
Pinus monticola, named by David Douglas after he found it growing on Mount St. Helens. The species name is Latin for “mountain dweller,” and that is where you can find it, growing throughout the mountains of the Pacific Northwest. It grows in the Cascades and in the Coast Range at elevations of 3000 to 5000 feet. In Washington and British Columbia, it grows right down to sea level. It also grows in northeast corners of Oregon and Washington, and in northern Idaho. It is the state tree of Idaho, where it’s sometimes called “Idaho pine.” In California, it grows in the Siskiyous and Sierras.

You may be surprised to find western white pines growing in the Coast Range of Oregon, but you can find some in the higher elevations. Some young ones grow in the Tillamook Forest near the top of the Storey Burn Trail, west of Storey Burn Road. In Portland, you can see several large western white pines at Hoyt Arboretum. They are growing along the Bristlecone Pine Trail. They are easy to identify by the labels on the trees and the banana-shaped cones on the ground. Again, don’t pick them up if you don’t want sticky fingers.

Western white pine was once abundant in its range, but disease and logging have greatly reduced its numbers. As with many other white pines, the bane of western white pine is white pine blister rust, a fungus introduced in North America from Europe over 100 years ago. Although the extensive stands of western white pine have been decimated by blister rust, the species has developed some resistance to the disease, and the Forest Service has a program for breeding rust-resistant trees. For more information, look here. Bark beetles also attack western white pine, especially after they have been weakened by blister rust.

Western white pine wood is described as nonresinous — no surprise, since it seems to send all that sticky resin to the cones. The wood is soft, straight and stable in character, which make it desirable for making moldings and window and door frames. The wood is light, attractive, and easy to work, making it ideal for wood carving. In the past, it was the primary source of match sticks.

Pollen cones

There appear to be few genetic differences between western white pines in different locations in the Pacific Northwest. So you can collect seeds from one habitat or elevation and successfully grow them elsewhere. The trees can readily adapt to different growing conditions. However, California populations do seem to be genetically distinct from those in the Northwest. The California trees are more resistant to white pine blister rust.


More info

Northwest Conifers
Gymnosperm Database 
USDA: Silvics of North America
Coniferous Forest


Wednesday, September 2, 2020

Alpine Conifers

The timberline in the mountains is a special place for conifers. Below the timberline, the trees grow tall. Visitors walk among the large trunks in deep shade under the canopy high above. However, at the timberline, the conifers are transformed into a completely different form. The timberline is often a park-like area that conifers share with grasses, shrubs and wildflowers. If the towering trees in the forests below remind us of the pillars of a great cathedral, the trees at the timberline elicit visions of heaven. Indeed, when the wildflowers bloom in summer, the streets there are paved with gold, as well as blue, red, and white wildflowers.
McNeil Point
McNeil Point on Mount Hood
Mountain hemlock

Yet, the beauty of these trees is forged in adversity. It is a wonder that conifers can survive at these high elevations where they can be completely covered in deep snow, where they can be blasted with ice crystals in fierce winds, and where their branches and even their roots can be frozen by severe winter temperatures. To survive here they must adapt. The short branches of subalpine fir and Pacific silver fir keep them from breaking when covered in snow. Mountain hemlock branches are bendable and small trees that are covered with snow bend to the ground and pop back up in summer. The drooping branches of Alaska cedar just don’t collect much snow. On the other hand, many species depend on deep snow to protect their roots from freezing. The snow also protects trees from high winds that would blast them with ice crystals.
Subalpine fir
The conifers that can survive these harsh conditions often grow in small clumps with just one or two larger trees, surrounded by a thicket of small trees. At the highest elevations, these conifers may grow in a stunted, krummholz form, often unrecognizable from their tall relatives below.
Mountain hemlock and whitebark pine

Whitebark pine
In his book, Timberline, Stephen Arno explains how these alpine conifers survive the extreme conditions at the timberline. Curiously, the winter conditions are not the limiting factor for these trees. Summer is the critical time when conifers must prepare for the winter. They must have enough time in the brief summer to put on new growth and for the new growth to become mature. Arno describes this maturation process as “hardening off of shoots.” This hardening enables the new growth to survive the winter. (Arno, p. 57)

Contrary to common sense, it is not only the cold of winter that is destructive to alpine conifers. It is also … wait for it … heat. Conifers prepare for cold weather in the fall when temperatures begin to drop below freezing. If needles do not mature in the summer, they can be damaged by frost. But warm weather can dry out the new growth in winter, especially when it is windy or sunny. This drying or “winter desiccation” can be fatal to needles that have not had a chance to mature in summer. This hardening protects the needles, enabling them to retain their moisture. You can look at damaged needles and tell whether they were damaged by frost or winter desiccation. Frost damaged needles shrivel and then turn black. Needles damaged by winter desiccation turn orange-brown. (Arno, p. 58)
Mount Rainier
The factor that determines the upper elevation limit for conifers is not how cold the winters are. Rather, it is how cold the summers are. Summer must be warm enough and long enough for new growth to become hardened to survive both frost and desiccation.

Late summer is a great time to visit alpine areas. The snows have melted, and wildflowers are taking advantage of their brief summer and blooming in abundance. These parklands of life living on the edge are unmatched in stunning beauty themselves. Also, the view there is often framed by picturesque, snow-capped mountain peaks.
Mount Hood
The most common conifers at the timberline are mountain hemlock, subalpine fir and whitebark pine. Look closely on the ground, too. You may see a mat of common juniper. To identify all the trees you find at the timberline, print this page: Alpine Conifers
Common juniper

Monday, July 6, 2020

Focus on Port Orford Cedar

Port Orford cedar is a large, attractive tree native to southwest Oregon. The leaves are small, flat scales, often with a white X pattern on the lower surface. This pattern is unique for cedars of the Pacific Northwest. The cones are round and woody, similar to Alaska cedar and many cypress cones. The bark is brown with flat ridges and furrows, becoming thick on old trees. The thick bark helps the tree resist fire. However, the bane of Port Orford cedar is a fungus that attacks the roots. The remaining stands not cut down for lumber have been decimated by this root rot, which arrived in the native forests in the early 1950’s.

Many conifers in the Pacific Northwest have a large range, sometimes extending to Alaska or California. Port Orford cedar? Not so much. It is confined to a small area along the Pacific Coast from Coos Bay, Oregon to the Klamath River in California, extending to 5000 feet in the Siskiyou Mountains. However, they may have had a greater range at one time. Or maybe some made a run to the north. They are still growing in a small area near Florence, Oregon. You can see some at the Darlingtonia State Natural Site, north of Florence.
Port Orford cedar cones

A fire in the early 1950’s burned a wide area of Portland’s Forest Park in the vicinity of Saltzman Road. During replanting, several locations were replanted with Port Orford Cedar for some reason (probably because native seedlings were in short supply due to replanting in the Tillamook State Forest). You can find these Port Orford cedars growing in Forest Park along the Wildwood Trail at miles 14.3 and 16.6. More grow at the top of the Dogwood Trail and above Leif Erikson Drive near the junction with the Cleator Trail. Hoyt Arboretum has a few Port Orford cedars, but many have succumbed to the root fungus. Infected trees first show brown leaves in the lower branches.Two healthy ones remain along the Lookout Trail. Most of the specimens along the Redwood Trail have been lost, but some new ones that are resistant to the root disease have been planted there.  These seedlings came from the Dorena Genetic Resource Center, which has been working with Oregon State University to research and grow Port Orford cedars that are resistant to the root disease.

Sign on the Redwood Trail at Hoyt Arboretum
Spring is a good time to look for Port Orford cedars, when their distinctive, pollen cones appear. They are small, like most pollen cones in the cypress family, but their bright red color is striking and unique.

Port Orford cedar pollen cones
The scientific name of Port Orford cedar is Chamaecyparis lawsoniana. The species name, lawsoniana was named after nurseryman Peter Lawson of Scotland, who distributed cultivars throughout Europe. Port Orford cedar is one of the most cultivated conifers, with over 500 varieties. They display an amazing variety of colors, forms, and sizes. 

Current uses of the wood are similar to western red cedar. The whitish wood is strong and resists rot, making it a desirable  alternative to western red cedar. It became popular in Japan because of its similarity to hinoki cypress (Chamaecyparis obtusa), one of the five sacred trees of Japan and an important tree used in Japanese architecture. However, limited supply and popularity in Japan have forced up the price of Port Orford cedar to levels among the highest for any Northwest tree.

Monday, June 22, 2020

Focus on Alaska Cedar

Years ago, I was working for a home builder in The Dalles, Oregon. At one point, the local lumber yard delivered a load of 2 X 4 Alaska cedar decking. As the load dropped to the ground, we noticed that the wood was a curious yellow color. Closer inspection revealed that the wood had a smooth, waxy surface and a distinctive, unpleasant smell. Some years later, while hiking on the south side of Mt. Rainier, I saw what looked to me like an Alaska cedar. To be sure, I stuck a knife blade into the trunk. Sure enough, when I pulled it out and smelled the blade, it smelled just like the 2 x 4 decking. It’s not often that it’s possible to identify a tree by its odor.

Alaska cedar is an attractive narrow tree, easily recognized by its distinctive drooping branchlets. The leaves are scaled with pointed tips that can be prickly. The small round cones are distinctive for conifers of the Cascades, although they look similar to those of Port Orford cedar, which grows along the south coast of Oregon. The bark is gray, and the stringy strips are often detached, giving it a scruffy look. When looking for Alaska cedar, don’t forget to also use your nose. When crushed, the leaves also have an unpleasant smell.

Alaska cedar grows in the upper elevations of the Cascades and Olympic Mountains. You can also find it throughout Southeast Alaska, where it grows down to sea level. In colder regions, it grows where there is deep snow, which protects its shallow roots from freezing. Ironically, the warming climate may cause freeze damage to the roots, as snowpacks become thinner. If you drive to Government Camp on Mt. Hood, you can see some Alaska cedar growing in town. You are likely to see Alaska cedar growing in urban areas, where its attractive, weeping form is desirable for plantings as an ornamental. A number of them are growing at Portland’s Hoyt Arboretum along Fischer Lane.

The wood of Alaska cedar is strong and resists rotting. Sometimes called yellow cedar, the wood is light yellow and turns brighter yellow when wet. The native people of Canada's west coast and Southeast Alaska made canoe paddles, bows, and many other tools and implements from Alaska cedar. Today it is used to make furniture, boats, window frames, shingles, and siding. You can find beautiful carvings of Alaska cedar in gift shops in Southeast Alaska.

Pollen cones

The scientific name of Alaska cedar is Callitropsis nootkatensis, formerly Chamaecyparis nootkatensis. The classification of this conifer has been the subject of much recent discussion and indecision among botanists. Other proposed genus names include Xanthocyparis, Cupressus and Hesperocyparis. The species name, nootkatensis, is derived from the name of the Nootka people of Vancouver Island. Oregon Flora shows Callitropsis nootkatensis as the name. Other common names include yellow cedar, Nootka cypress, yellow cypress, and Alaska cypress.

Note: Like the other cedars of the Pacific Northwest, Alaska cedar is not a true cedar. That is, its genus is not Cedrus, the genus of the true cedars from the Middle East and Himalayas. Some writers indicate this by writing the name as "Alaska-cedar."

More Info

Tuesday, June 9, 2020

Focus on Incense Cedar

My first encounter with incense cedar wasn’t a sighting. It was a smelling… of trees in Yosemite Valley below Yosemite Falls. Walking through the trees there, I noticed the pleasant aroma and asked a ranger what it was. He told me I was smelling incense cedar. With such an overpowering aromatic presence, this tree is well-named. These aromatic qualities have contributed to its wide use in cedar chests and closets. Its resistance to decay makes it a good choice for siding and other outdoor uses.

You may not realize it, but you have most certainly used small amounts of incense cedar. It has been the preferred wood for making pencils for many years. However, planting incense cedar as an ornamental is surely more noble than its use in pencils. Its slow growth and beauty make it a preferred landscaping tree. Incense cedar displays bright pollen cones in the fall. You often see them on branchlets in Christmas wreaths.

Leaves and pollen cones
Incense cedar has small, flat scale-like leaves forming overlapping, long, wedge-shaped joints. The leaves are often described as forming the shape of a wine glass, but beer drinkers would swear that they are shaped like a beer glass. This pattern, often outlined in white, is distinct to incense cedar. The foliage forms flat sprays that often have a vertical orientation, unlike western red cedar, which has drooping sprays with a horizontal orientation.

The reddish-brown bark looks similar to western red cedar, but it is deeply furrowed on large trees. The best way to identify incense cedar is by its unique cones if any are present. The differences that distinguish incense cedar leaves and bark from other cedars may be subtle, but incense cedar cones are unmistakably unique. They are shaped like a duck's bill, and when they mature, they open, looking like an open bill with its tongue sticking out.

Incense cedar is primarily a California tree, growing in the mountains throughout the length of the state. But some grow in the Oregon Cascades north to the south slopes of Mt. Hood. None are native to the Washington Cascades, at least, not yet. As the climate warms, they may be headed north. While our other cedars in the Pacific Northwest (western red cedar, Alaska cedar, and Port Orford cedar) favor wet areas, incense cedar tolerates dry conditions. It is moderately shade tolerant, but less so than our other native cedars. You can find incense cedar growing in the southern parts of the Mt. Hood National Forest. As you travel south in the Cascades, they become more common, also growing in the coastal mountains of southwest Oregon. If you want to see incense cedar in the Portland area, several were planted at Hoyt Arboretum along the connector trail between Bray Lane and the Redwood Trail. More are growing along the Marquam Trail, west of the Vietnam Memorial.

The scientific name of incense cedar is Calocedrus decurrens. Calocedrus means "beautiful cedar." Decurrens describes how the leaves extend down the stem. The English form of the word is "decurrent."

Note that the cedars native to North America are not true cedars. That is, they do not belong to the genus Cedrus, the genus of the cedars from the Middle East and Himalayas. Common names often can be misleading. However, did you notice that cedrus is embedded in the genus name of incense cedar? Even the scientific name suggests a close relationship to the genus Cedrus. Scientific names can be misleading, too.
See also
New World Cedars
Western Red Cedar

Monday, May 25, 2020

Focus on Mountain Hemlock

“My God. It’s full of stars.” This is what Dave Bowman exclaimed when he looked into the monolith orbiting Jupiter in the classic science fiction movie 2001: A Space Odyssey. If he had looked at a mountain hemlock, he might have said the same thing. The needles at the tips of the twigs often look like tiny stars with bright blue-white beams of needles radiating out from a point. The needles of other hemlocks tend to lie flat and have white stomatal bands only on the lower surface.

With complete disregard to any sense of order, the needles of mountain hemlock point in all directions. The needles are short like Western Hemlock, but they have white stomatal bands on both sides of the needle, often giving it a bluish color. The leader at the top of the tree curves and droops over like Western Hemlock. The cones of mountain hemlock are also distinctive. They are about two inches long, three times the size of other hemlocks. In fact, mountain hemlock is so different from other hemlocks that some botanists once thought that it was a hybrid between hemlock and spruce.

Tsuga Mertensiana is the scientific name of mountain hemlock. Tsuga is the Japanese name for hemlock.  The species name, mertensiana, comes from Karl H. Mertens, a German botanist, who first collected specimens in southeast Alaska while on a Russian expedition in 1827.

Mountain Hemlock grows in the higher elevations of the Cascades and Olympic Mountains, often at the timberline with subalpine fir and whitebark pine. Below the timberline, it sometimes grows in pure stands of large trees. However, at the timberline, it often remains a dwarf, creeping shrub, where winter snow flattens it to the ground. In these park-like settings, the hemlocks also grow in clumps, which contain one or more old, large trees and several young trees. The range of mountain hemlock extends into the High Sierras of California, where it grows at higher elevations, the northern Rocky Mountains, and along the coast of Alaska to Anchorage, where it grows down to sea level.

Mountain hemlock at Gnarl Ridge

As you gain elevation when hiking in the mountains of Oregon, you will see mountain hemlocks growing among the western hemlocks, starting at about 3500 feet elevation. By the time you reach 4500 feet, the western hemlocks give way to mountain hemlocks. However, you don’t have to drive up to the mountains to find mountain hemlocks. You can see them planted as ornamentals in urban areas. Look for the bluish color and the drooping top. They thrive even at lower elevations, but grow slowly, which makes them a fitting landscaping tree.

Mountain hemlock has little value as lumber. However, it is an important factor in watershed protection, a fact not lost on people in Portland, which gets its water from Bull Run Lake near Mt. Hood. The water from Bull Run is renowned for its purity, thanks to the mountain hemlock and other trees in the forest above the lake. We can also appreciate the scenic beauty of mountain hemlocks growing in and around grassy alpine meadows. You can see them at Paradise on the south slope of Mount Rainier, at Elk Meadows east of Mount Hood, in Jefferson Park on the north side of Mount Jefferson, and in the Three Sisters Wilderness.

John Muir was impressed by the contrast between its delicate appearance and its ability to thrive in the harshest conditions, spending the long, cold winter at the timberline under many feet of snow. “No other of our alpine conifers so finely veils its strength. Its delicate branches yield to the mountains' gentlest breath; yet is it strong to meet the wildest onsets of the gale,—strong not in resistance, but compliance, bowing, snow-laden, to the ground, gracefully accepting burial month after month in the darkness beneath the heavy mantle of winter…. Thus warmly wrapped they await the summer resurrection. (The Mountains of California, Ch 8 “The Forests”) Curiously some observers have noted that mountain hemlocks may need the protection of all this snow. The roots may freeze in cold environments where there is little snowfall. Heavy snowfall can insulate these delicate roots. John Muir called the mountain hemlock “... ineffably beautiful, the very loveliest of all the American conifers.” (The Yosemite, Ch. 6) Mountain hemlock is one of my favorites, too. Look for them the next time you’re up in the mountains or shopping at a local nursery.

See also
Focus on Westerm Hemlock

More info on mountain hemlock
Gymnosperm Database

Thursday, May 21, 2020

Focus on Hemlocks

Hemlock trees are not the source of the poison hemlock that killed Socrates. They are not poisonous and not even related to poison hemlock, but the foliage looks similar, and crushed needles have a similar smell. This, no doubt, led European settlers of North America to call these trees hemlocks. The scientific name of the hemlock genus is Tsuga, which also has a curious origin. Rather than the usual Latin name, Tsuga is the Japanese name for Japanese hemlock. In the nineteenth century, hemlocks were first classified as a pine, then as a fir, and later as a spruce. After the discovery of Japanese hemlock, hemlocks were assigned to the genus Tsuga.

Hemlocks are in the pine family (scientific name: Pinaceae) and are unique in the family. They have a distinctive drooping leader at the top of the tree. Hemlocks also have the smallest cones in the pine family. They can tolerate growing in the shade of other large trees for years. However, hemlocks can grow to enormous size and eventually dominate other trees in the forest. Although they can grow in the shade of Douglas fir for hundreds of years, in the normal succession of a Douglas fir forest, the hemlocks will eventually prevail, forming the canopy of the mature forest.

Western hemlock
At least nine species of hemlock grow in North America and Asia. Curiously, they are absent from Europe. Four species are native to North America, with two of them in the Pacific Northwest, western hemlock and mountain hemlock. They are important commercial trees, used to make lumber, plywood and pulp for paper. However, the beauty of their drooping form and delicate branchlets far exceeds their usefulness as lumber. And pulp? How degrading. Their purpose is better served by horticulturists, who have developed many popular cultivars.

Mountain hemlock
Hemlock needles are short and usually flattened on the twig, but they have a tendency to deviate from their flattened position. The needles are dark on top with two white lines on the lower surface. The cones are usually less than an inch long, and the scales are thin and rounded. Mountain hemlock is an exception to these characteristics, with bluish needles that make no pretense about lying flat, surrounding the twig in all directions. Also, the cones are over achievers, being twice as large as other hemlock cones.

Western hemlock at Elk Mountain
Hemlocks flourish in wet, cool environments. They can tolerate a heavy snowpack, not with strength, but by bending. They will spring back when the snow melts in the spring. On the other hand, one thing they do not tolerate is drought. Unless you live east of the Cascade Mountains, a hemlock would be a graceful addition to your yard, whether it is a cultivar or one of our natives.

More info
Tsuga at
Tsuga in Wikipedia