''Betula cordifolia'', the mountain paper birch (also known as mountain white birch or eastern paper birch) is a

birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus ''Betula'' contains 30 ...

species native to

Eastern Canada Eastern Canada (also the Eastern provinces or the East) is generally considered to be the region of Canada south of the Hudson Bay/Strait and east of Manitoba, consisting of the following provinces (from east to west): Newfoundland and Labrador, ...

and the

Northeastern United States The Northeastern United States, also referred to as the Northeast, the East Coast, or the American Northeast, is a geographic region of the United States. It is located on the Atlantic coast of North America, with Canada to its north, the Southe ...

. Until recently it was considered a variety of ''

Betula papyrifera ''Betula papyrifera'' (paper birch, also known as (American) white birch and canoe birch) is a short-lived species of birch native to northern North America. Paper birch is named for the tree's thin white bark, which often peels in paper like ...

'' (paper birch), with which it shares many characteristics, and it was classified as ''B. papyrifera'' var.'' cordifolia'' (Regel) Fern.Farrar, J. L. (1995). ''Trees in Canada''. Markham: Fitzhenry and Whiteside Ltd.

Description

''Betula cordifolia'' is a

deciduous tree In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

that reaches heights of about 60 feet or 25 m and a trunk diameter of about 30 inches or about 75 cm.Powell, G., Beardmore, T. ''New Brunswick Species of Concern: A field guide''. p.17–19. Retrieved from Mature bark is white or bronze-white, peeling in thin layers. The inner surface of the bark is copper-coloured and the young bark is shiny brown with pale brown

lenticels A lenticel is a porous tissue consisting of cells with large intercellular spaces in the periderm of the secondarily thickened organs and the bark of woody stems and roots of dicotyledonous flowering plants. It functions as a pore, providing a ...

. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are alternate, ovate, 6–12 cm long, and double-toothed. As the specific epithet suggests, the leaf base is generally

cordate Cordate is an adjective meaning ' heart-shaped' and is most typically used for: * Cordate (leaf shape) The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a ...

(heart-shaped), however this can be misleading as it is occasionally flat or rounded. The leaves are dotted with many resin glands and the

buds In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of a stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be specia ...

are ovoid and blunt. The twigs are yellow-brown to dark-brown and are dotted with resin glands and gray lenticels. They lack the hairs found on ''Betula papyrifera''.Ryan, A. G. (1978). ''Native Trees and Shrubs of Newfoundland and Labrador''. St. John's: Parks Division, Government of Newfoundland and Labrador. The

flowers A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

are

catkins A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged cl ...

, with

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

catkins 2–4 cm long and

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

catkins 1–2 cm long. The seed catkins mature to about 3–5 cm long and bear winged nutlets about 2–3 mm long.

Distribution

''Betula cordifolia'' is found in

Atlantic Canada Atlantic Canada, also called the Atlantic provinces (french: provinces de l'Atlantique), is the region of Eastern Canada comprising the provinces located on the Atlantic coast, excluding Quebec. The four provinces are New Brunswick, Newfoundlan ...

Quebec Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...

, northwestern

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

, Northern

New York State New York, officially the State of New York, is a state in the Northeastern United States. It is often called New York State to distinguish it from its largest city, New York City. With a total area of , New York is the 27th-largest U.S. stat ...

, and

New England New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and by the Canadian provinces ...

. It is generally found in northern habitats or high elevations, particularly on moist ground. It is also found at high elevations on the slopes of the Black Mountains in Western

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

Distinctions from ''Betula papyrifera''

''Betula cordifolia'' and ''Betula papyrifera'' are very similar species, indeed they were once considered the same species. The primary methods of distinguishing the one from the other include: * ''Betula cordifolia'' is only found in the Eastern part of North America * Its leaves are dotted with resin glands * The leaf base is cordate (heart-shaped) * Young shoots are not hairy. * It is generally diploid (28 chromosomes) Since many of these characteristics vary from tree to tree, ideally several of these characteristics should be noted before making a positive identification. It has been suggested that ''Betula cordifolia'' and ''Betula papyrifera'' hybridise, however this is unlikely given the more recent evidence of different chromosome numbers. The trees make nearly identical bark, sapwood and heartwood. Both species are mainly used for manufactured wood products, such as lumber, plywood, OSB, paper pulp and wood pellets. As processed firewood, both species produce excellent heat, but burn relatively quickly, however with little to no smoke. The most conclusive method of identification is from chromosome analysis.

References

{{Taxonbar, from=Q2900277 cordifolia Trees of Canada Trees of the Great Lakes region (North America) Trees of Eastern Canada Trees of the North-Central United States Trees of the Northeastern United States Trees of the Southeastern United States Trees of Ontario Trees of Quebec Plants described in 1861