Hansen's Northwest Native Plant Database


Betula papyrifera (Paper Birch, Canoe Birch, American White Birch)

 

Kingdom

:  

 Plantae – Plants

Subkingdom

:  

 Tracheobionta – Vascular plants

Superdivision

:  

 Spermatophyta – Seed plants

Division

:  

 Magnoliophyta – Flowering plants

Class

:  

 Magnoliopsida – Dicotyledons

Subclass

:  

 Hamamelididae

Order

:  

 Fagales

Family

:  

 Betulaceae – Birch family

Genus

:  

 Betula L. – birch

Species

:  

 Betula papyrifera Marsh. – paper birch

Plant Brief: A beautiful, native birch, this tree should grace every garden.

Mature trees have white bark that peels off in thin layers. The heart-shaped leaves are larger than European birches, averaging 3”x2,” and these natives hold their white bark color well. In fall, the leaves of paper birch reliably turn a cheerful yellow color.

This tree is especially attractive in clumps, which frequently occur in the wild, and can attain heights of 100.’ It grows well in moist, not soggy, soils in full sun. Hardy to USDA zone 2, Paper Birch is found throughout all of North America.

Paper birch gives that touch of class and elegance to the native garden.

Description: Often seen in Native American themed paintings by Bev Doolittle, the white bark of the Paper Birch has long been a favorite subject for artists and gardeners alike. The elegant Paper Birch positively catches your eye when you come upon the pure stands of snow white slender trees with long flowing branches.

The supple, slender twigs slightly droop so that they drift with the wind.

In the crowded forest, it is more common growing as a slender, narrow form but in the open the tree has an expansive crown that begins branching near the base of the trunk.

A fairly large tree, the birch reaches a height between 70 to 100 feet and 14 to 24 inches in diameter.

The tree may grow with either a single or multi-stemmed trunk and smooth coppery brown or papery white bark patterned with dark, elongated horizontal pores called lenticels. The marvelous white bark of mature trees peels off in thin sheets of waterproof paper.

If you look closely at the young twigs, you’ll sometimes be able to see small hairs and a few crystalline-warty glands. The species name Betula is translated to mean “pitch,” while papyrifera is derived from the Greek word papyrus that means “paper,” and the Latin word firo that is translated into “to bear or carrying.” Therefore papyrifera means “paper bearing.”

Its graceful form and wonderful white bark make Paper Birch a desired ornamental. With an open setting the highly adaptable tree does well even in very harsh environments.

Habit: Paper Birch leaves suspend alternately off the long willowy twigs. The triangular to oval shaped leaves taper to sharp points and are approximately 2 to 4 inches in length. If you examine the leaf margin above the leaf base you’ll notice that the shallowly toothed margins are doubly serrate. The dark green leaves are paler underneath –- look for the tufts of hairs found at intersections of veins on the underside of the leaf.

The separate male and female flowers are borne as pendulous catkins. Apetalous (having no petals) catkins appear on the same tree in spring cascading from the tips of paper birch branchlets.

The male catkins begin forming in the fall and become partially enlarged before growing dormant for the long months of winter. Come spring the larger male catkins begin developing again, lengthening to 3 or 4 inches when mature.

Female catkins appear in springtime along with the emergent foliage and mostly remain as erect spikes that reach about 1 inch in length.

The ripened brown cone-like fruit can be found anytime from late August to November. Each fruit (strobilus) has numerous scales sheathing the tiny winged seeds called nutlets. The rounded nutlet wings are taller and wider than the seed itself. These teeny seeds are often carried off by the wind as soon as they ripen.

The young coppery birch can easily be confused with Bitter Cherry (Prunus emarginata), but a quick check of the leaves will determine the right species. Cherry leaves are oblong in outline and have a bluntly tapered tip, while the Paper Birch leaf is more triangular in shape and has a sharp pointed tip. If you happen to have a magnifying lens, look for small glands positioned at the base of the cherry tree’s leaf blade.

Habitat and Range: Paper Birch is one of North America’s most far-spread tree species. This resilient species has evolved to flourish in cold climates. The ever-present tree grows all across Canada and southern Alaska as well as most northern states in the US. Other Paper Birch populations can be found in parts of Colorado, Montana, the eastern Cascades, the Great Lakes states, and North Carolina. You will find Paper Birch scattered among the forested slopes of mountain ranges from low valleys to subalpine copses.

In Canada, this beautiful birch is found in the flat boggy muskegs of boreal forests, and across its range it can persist in the saturated soils of swamps and other wetlands. Well-drained sandy soils are favored by the tree, but it tolerates a wide range of soil textures from gravel to silt as well as organic bog or peat soils.

In exposed areas the tree can form pure stands, but in the shade of a forest it will only be found in scattered openings. A pioneer species, the shade intolerant tree is one of the first colonizers of fire disturbed or clear-cut lands. This avid re-seeder rapidly pervades severely disturbed lands.

The thick stands provide cover and enrich the disturbed soil, which leads to the succession of new shade tolerant species. There are many varieties of the Paper Birch species.

The tree is a genetically malleable species and hybridization between different varieties is quite common.

Ornamental Values: Commonly used in landscapes as a shade tree, the paper birch’s graceful appearance and brilliant white bark make it a favored ornamental. Though, you will have to wait approximately 10 to 12 years before the bark becomes the tell-tale striking white color.

Be careful where you plant this tree, its roots love to invade water pipes and sewer lines. Paper birch is a rather short-lived tree (in the tree world, that is) that can live up to 140 years.

It has a shallow root system and typically reaches less than 2 feet beneath the soil surface.

The deciduous foliage has a high decomposition rate and rapidly forms deep rich soils.

Native Plant Gardening/Wildlife Habitat: The birch canopy can be filled with an orchestra of birds including sapsuckers, woodpeckers, and kinglets feeding upon insects or the tiny nutritious seeds.

Birch trunks house cavity-nesting birds such as woodpeckers, chickadees, and nuthatches.

You can often find yellow-bellied sapsuckers hopping up and down the tree trunk, poking holes with their beaks to get a taste of the sap. The open sap holes are revisited by clever hummingbirds and squirrels.

Various insects as well as swallow tail butterfly larvae regularly feed upon the foliage.

Paper Birch bark is important to woodland creatures as well. The bark is gathered by birds for nesting material and small mammals feed on the leaves, twigs, and wood of the tree.

Paper Birch is important browse for moose, deer, and snowshoe hares.

Porcupines nibble on the tender inner bark, and voles and shrews snatch up the seeds.

The stands of trees offer choice shelter for deer and elk.

Plant communities that are home to paper birch may also include Quaking Aspen (Populus tremuliodes), Balsam Fir (Abies balsamea), Black Spruce (Picea mariana), Kinnikinnik (Arctostaphylos uva-ursi), Beaked Hazel (Corylus cornuta), Gooseberry (Ribes oxyacanthoides), Red Elderberry (Sambucus racemosa), Blueberries (Vaccinium species), Bracken Fern (Pteridium aqualinium), Shineleaf (Pyrola species), Wintergreen (Gaultheria procumbens), raspberries and blackberries (Rubus species), Green Alder (Alnus crispa), Scouler Willow (Salix scouleriana), and roses (Rosa species).

Restoration and Mitigation Values: The pioneering nature and ability to flourish on disturbed sites makes Paper Birch a wonderful choice for some re-vegetation and restoration projects.

The inherent qualities of this species allow them to occupy lands that would otherwise be considered uninhabitable by most plants and animals. Projects involving mining spoils and other toxic sites may use the birch to cleanse the soils and initiate the process of succession for other native species.

It tolerates wetland environments, but also does well in drier upland habitat.

Historical and Cultural Uses: This valuable species was often used by different Native American peoples. The bark was fashioned into baskets, storage containers, mats, baby carriers, moose and bird calls, torches, household utensils, and not surprisingly canoes.

The strong, flexible wood was often worked into weapons such as spears and bows and arrows.

Commercially, Paper Birch is processed into wood chips for the manufacture of pulp wood and fuel. The tough, durable lumber is used to construct boxes, plywood, veneer and other ornaments. The wood is simple to work with and readily accepts stains and finishes.

Restoration and Mitigation Values: The pioneering nature and ability to flourish on disturbed sites makes Paper Birch a wonderful choice for some re-vegetation and restoration projects.

The inherent qualities of this species allow them to occupy lands that would otherwise be considered uninhabitable by most plants and animals. Projects involving mining spoils and other toxic sites may use the birch to cleanse the soils and initiate the process of succession for other native species.

It tolerates wetland environments, but also does well in drier upland habitat.

Historical and Cultural Uses: This valuable species was often used by different Native American peoples. The bark was fashioned into baskets, storage containers, mats, baby carriers, moose and bird calls, torches, household utensils, and not surprisingly canoes.

The strong, flexible wood was often worked into weapons such as spears and bows and arrows.

Commercially, Paper Birch is processed into wood chips for the manufacture of pulp wood and fuel. The tough, durable lumber is used to construct boxes, plywood, veneer and other ornaments. The wood is simple to work with and readily accepts stains and finishes.

The bark is a favorite craft material and is often used to wrap candles.

Edible and Medicinal Uses: The edible sap can be boiled down to make sweet syrup. The sap is also collected to make wine, beer and soft drinks as well as health tonics. Reportedly the Native Americans chewed birch gum resin, either for its disinfectant properties or perhaps for a slightly energizing effect produced by terpene compounds. In an emergency the tender inner bark can be eaten.

NOTE: Please use caution when preparing or eating any parts of a plant. Identification of the species and knowledge of a plant’s toxicity are both essential before using any plant species medicinally or otherwise. Please consult with a heath professional before attempting to treat any ailment.

Three More for Breakfast

By Bev Doolittle

Propagation Techniques: Seeds -- This species is a good seed producer. Under good growing conditions it may begin producing mature seed by age 15, but the most prolific years of seed production averages from age 40 to age 70. To gather seeds, collect the still green strobiles and spread them out to dry.

Once dry, place the fruits into a bag and shake or flail vigorously to break the strobiles into individual seeds. Sift the shattered strobiles through a screen or use a fanning motion to separate the seed from the fruit debris. The seed has a thin coat and easily germinates once exposed to light and warm temperatures. Germination is best in moist, shady spots but the seedlings require a bit more sun for the first year. The seedlings are best grown on humus seedbeds in moderate or full sunlight.

You may store the birch seeds in an airtight container at room temperature for about 2 years, but for longer storage the seeds will have to be chilled. The seeds will need to be kept at low moisture content for them to last for any amount of time.

If you are germinating stored seeds, they may benefit from a pre-chilling treatment. The young seedlings should remain in the beds for 2 years before transplanting them.

Vegetative -- Different techniques of vegetative propagation are also an option for reproduction. Cuttings can be grown, but you must make sure to gather the shoots at the right time. The shoots must be still actively growing -- check to make sure the base of the shoot is just beginning to become rigid. Gather 3- to 4-inch cuttings and dip in a rooting hormone before placing in a well-drained medium. The species is also reproduced by grafting, air layering, root cuttings, and tissue culture.

Common Diseases: Rust is a common problem in nurseries and is brought about during cool, wet weather. Look for small angular spots on the leaves and reddish yellow pustules on the undersides of the leaf. By fall the entire leaf will be black or brown. Rust can easily be treated with a fungicide application.

The bronze birch borer is the only serious threat to natural populations, but the insects will only kill trees already weakened by some other disturbance.

It is also possible to have a number of different bacterium and fungi enter the tree through wounds and branch stubs.

If root rot fungus infects the root systems of surrounding trees, the birch roots are susceptible to the disease if they come into contact with them. You will notice the telltale signs of the disease by the appearance of cracks in the bases of stems, collar cracks, and the whole tree may easily uproot.

This engraving (at right) is from the 1924 edition of Oregon State's Beaver.

This old tree stands at the entrance of Walling Pond in Salem. It has been trimmed periodically by the electric and telephone companies whose wires it sometimes reaches to entwine. As a result, it has a lot of sucker branches and twigs that would not be present had it been left alone. Nobody knows who planted it. I imagine it simply volunteered to grow right where it is.

I took its picture one Thanksgiving evening while I waited for just the right sunset colors. I wanted a shot of the gravel company's industrial building where Old Glory flew and I had in my mind an image I hoped to capture.

      

Above left, one of several birdhouses hangs from the birch with large rhododendron in the background. Above center, a birch 'flower.' Above right, yellow-golden Paper Birch leaves, catkin, 'flowers,' atop the mossy path.

Living among Paper Birch trees has given me an opportunity to learn first hand the day-to-day behaviors of this delightful native tree. When I first saw the garden here it was mid-August. The birches were fully clothed in bright green leaves, their sparkling white bark gave a cooling feel in this grove of 17 oldsters. At their feet were mature rhodies, some azaleas, and borders of native and cultured violets. The paths around the house were lush green moss, broken by roots and rocks, and starred with what I thought were light blue flowers.

As summer transitioned into fall, more flowers appeared--so many I began to investigate native mosses to identify their species. I had never heard of a moss with this profusely blooming habit. I ultimately discovered that the flowers were not growing in the moss. Instead, they were floating down and peppering the moss from some nearby source. I looked at neighboring gardens all around my house but did not find what I imagined would be a flowering tree or shrub or hardy perennial. By now it was late September and no likely plant was evident.

Finally, I looked again at my own back yard and spied the little flowers wafting on a slight breeze down from right over my head. The 'flowers' were emanating from the catkins on my Paper Birches! As the catkins ripened, the tiny flowery elements separated from each main catkin stalk and landed on my moss as well as on the rhodie leaves, my decks--just everywhere! In the photo above right you can see a fresh green catkin as well as some that are spent and some of the little 'flowers' above and below the fallen birch leaves. And, another discovery, the 'flowers' are actually shaped in a sort of fleur-de-lis, not the petals I originally thought them to be.

Now that autumn has taken over the garden, the plentiful birch leaves will soon be providing mulch throughout the landscape while the empty arms of the birch trees shine white in darkest winter and their texturally interesting bark peels randomly in curious patterns.

Below left, looking up into the birches we see some have turned golden while others are still green--an unusual sequence for fall 2011. Below center, a few autumn birch leaves on my lower deck. Below right, a beautiful rainbow framed by two of my birches with arborvitae between my yard and my neighbor's.

   

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Thank you to the following references for their invaluable information:

Plants of the Pacific Northwest Coast by Pojar and Mackinnon (1994)

Western Forests, A National Audubon Society Nature Guide by Stephen Whitney (1985)

Plants of the Pacific Northwest Coast by Pojar and Mackinnon (1994)

Western Forests, A National Audubon Society Nature Guide by Stephen Whitney (1985)

Flora of the Pacific Northwest by C.L. Hitchcock & A. Cronquist (1973)

Trees, Shrubs, & Flowers to know in British Columbia & Washington by C.P. Lyons (1995)

Collecting, Processing and Germinating Seeds of Wildland Plants by J.A. Young and C.G. Young (1986)

Trees to know in Oregon by Oregon State University Extension Service & Oregon Department of Forestry, Extension Circular 1450 (1995)

The Reference Manual of Woody Plant Propagation from seed to tissue culture by M.A. Dirr and C.W. Heuser, Jr. (1987)

Landscaping for Wildlife in the Pacific Northwest by Russell Link, University of Washington Press & Washington Department of Fish & Wildlife (1999)

US Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (2002, February) http://www.fs.fed.us/database/feis/

A Boundary Waters Compendium http://www.rook.org/earl/bwca/nature/trees/betulapap.html  

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