Paper Birch is a native tree with a narrow open crown with slightly drooping to horizontal branches in the lower part, ascending branches near the top. It grows 50 to 70 feet in height. Often several trunks will develop and in home landscape plantings that seems to be in favor.
The bark is smooth, thin, chalky to creamy white with long horizontal lines. The bark separates into papery strips which reveals the pink to orangish inner bark. With age, the bark becomes furrowed and scaly near the base of the tree with the lenticels much expanded.
Twigs are slender, reddish-brown and smooth to slightly hairy. There are light colored lenticels on young branches. Stems of recent years are still reddish-brown before turning to the chalky white. Buds are green and brown, slender and lateral buds are sticky. There will be spur shoots with buds on older growth that produce a cluster of 2 to 3 leaves. There is no odor or taste of wintergreen when cut.
Leaves are alternate, simple, ovate, about 3 to 5 inches long, with double saw-toothed irregular edges, a stalked rounded to heart shaped base, pointed tip, dull dark green on top and paler yellow-green and nearly hairless below; 5 to 9 veins on each side which terminate at a large tooth. Small resinous glands may be present of the major veins. Light yellow color in autumn.
Flowers: The tree is monoecious, that is with separate male and female flowers. Male flowers (staminate) first form in the fall near the ends of the twigs in groups of 2 to 5, remain dormant over winter and then elongate in the spring, into long hanging catkins, up to 5 inches long. The individual flowers are only 1/8 inches long, are in clusters of 3 on the catkin, are yellowish with 2 stamens, a 4-lobed calyx and are somewhat obscured by small bracts. Female flowers (pistillate) appear before the leaves are fully expanded and are greenish upright catkins, known as 'aments', about 1 to 2 inches long, back of the tip on the same twigs as the male catkins. They have an ovary, a pair of styles but no calyx or petals. Like the male flowers, they are in clusters of 3 on the catkin and obscured by bracts. The bracts form 13 spiral lines around the catkin.
Fruit: Pollination is by wind. Flowers mature to a drooping cylindrical non-woody cone, brownish in color. The bracts become dry scales at maturity, each scale having three lobes and three winged seeds attached; each seed a 2-winged nutlet, of which there are many per cone and which disperse by wind and water in late autumn and over winter. The nutlet wings are thin, papery, that are much broader than the nutlet itself. Seed production begins when a tree is about 15 years old.
Habitat: Paper Birch grows in many environments from moist marsh areas to uplands including some high altitude locations. It has adapted to landscape plantings and grows well if adequate moisture is provided. Full sun is best- it tolerates some shade but not deep shade. It is a short-lived tree and is frequently attacked by the Bronze Birch Borer (Agrilus anxius). It does not spread from its root crown, but will re-sprout from a stump. Paper Birch is usually a first generation species in an area and is not dominant, being replaced by more mixed-wood species.
Names: The genus, Betula, is the Latin word for the birch tree. The species, papyrifera, comes from papyrus, and refers the inside of the peeled bark on which you can write, like on papyrus. The name 'birch' itself is derived from an old Teutonic word. The author name for the plant classification, ‘Marshall’ is for Humphry Marshall (1722-1801), American Botanist, who published in 1785 - Arboreteum Americanum: The American Grove, an Alphabetical Catalogue of Forest Trees and Shrubs, Natives of the American United States. The alternate name of 'Canoe Birch' is a reference to Native American use of the large sheets of the peeling outer bark to enclosed the frame of a canoe. (see details at bottom of page.)
Comparisons: Many Birch leaves may look alike, but the bark of most species is different. The closest comparison to the bark of paper birch is that of the River Birch, B. nigra, but there the bark peels in more scale-like clusters, not in strips, and the base of older trees is more deeply furrowed. See leaf comparison photo below.
Above: 1st photo - Landscape trees are often selected with multiple trunks, which occur naturally. 2nd & 3rd photos - The bark has long horizontal lines and separates into papery strips which reveals the pink to orangish inner bark. With age (2nd photo), the bark becomes furrowed and scaly near the base of the tree with the lenticels much expanded.
Below: 1st photo - Male catkins at the ends of branches in early spring before elongation. 2nd photo - Twigs are not creamy white. Lateral buds often occur on spur shoots as shown. These develop 2 to 3 leaves. 3rd photo - Stems of young age are still reddish-brown as seen at the top of these trees, before turning to the chalky white.
Below: 1st photo - The under side of the leaf is a pale green, while the upper side (2nd photo) is darker green. Note the double sawtooth margins and how veins terminate at a large tooth.
Below: 1st photo - Just back of the twig tip behind the male catkins are the smaller female catkins which will elongate into a green cone which then turns brown at maturity of the seeds. 2nd photo - Detail of the male flowers - 3 to a group with a brown bract covering.
Below: 1st photo - The male catkins first form in the fall and overwinter, then in spring, they elongate and produce the pollen bearing small flowers. Behind them on the twig are the smaller female catkins (aments). Drawing from Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York.
Below: In previous decades the population of paper birch in the Garden was much greater. This winter view was taken Martha Crone on Nov. 8, 1951. Changing moisture levels and the succession of species have caused the changes.
Below: This historical photo from the 1920s shows grouping of Paper Birch in the original Woodland Garden. Both historical photos courtesy Minnesota Historical Society, Martha Crone Collection.
Below: A comparison of leaves of the five Birch species described on this site.
Notes: Paper Birch is indigenous to the Garden. Eloise Butler cataloged it on April 29, 1907. It is less extensive in the Garden today than prior to 1960. Paper Birch is found throughout North America northward from the area of Colorado to Tennessee to North Carolina. In Minnesota it is found in most counties except those of the drier prairie area of the SW quadrant.
Eight species of birch are recorded from surveys in Minnesota. Three of them are crosses formerly reported but there are no known populations. The other five are native and are: B. alleghaniensis, Yellow Birch; B. cordifolia, Heart-leaved Birch; B. nigra, River Birch; B. papyrifera, Paper Birch; and B. pumila, Bog Birch. All but B. cordifolia are in the Garden.
Uses: Paper Birch is used extensively for specialty products requiring light soft but sturdy wood such as clothes pins, chopsticks, spools, etc., and also for pulpwood and plywood. To a certain extent it is widely used in cabinetry, especially in veneer form, but Yellow Birch is more highly sought for that use. If you want bursts of flame in a campfire, put on some Paper Birch bark.
The common name of "canoe birch" is reference to the native American use of Birch bark from the paper Paper Birch for canoe covering. Not only was it easy to obtain large strips but the bark has a large oil content making it waterproof. Here is a description by Francois Michaux, from his North American Sylva of 1841: "To procure pieces, the largest and smoothest trunks are selected: In the Spring two circular incisions are made several feet apart, and two longitudinal ones on opposite sides of the tree; after which, by introducing a wooden wedge, the bark is easily detached. These plates are usually ten or twelve feet long, and two feet nine inches broad. To form the canoe, they are stitched together with fibrous roots of the White Spruce, about the size of a quill, which are deprived of the bark, split, and suppled in water. The seams are coated with the resin of Balm of Gilead. Great use is made of these canoes by the savages and by the French Canadians in their long journeys into the interior of the country; they are very light, and are easily transported on the shoulders from one lake or river to another, which is called the portage. A canoe calculated for four persons with their baggage weighs from forty to fifty pounds."
Medicinal: There is limited literature on Native and folk use of the tree for treating ailments.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"