Betula cordifolia
Encyclopedia
Betula cordifolia is a birch
species native to Eastern Canada
and the North Eastern United States
. Until recently it was considered a variety of Betula papyrifera (Paper Birch), with which it shares many characteristics, and it was classified as B. papyrifera var. cordifolia (Regel) Fern.
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. The leaves
are alternate, ovate, 6–12 cm long, and double-toothed. As the species epithet suggests, the leaf base is generally cordate (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 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. The flowers are catkins, with pollen
catkins 2–4 cm long and seed
catkins 1–2 cm long. The seed catkins mature to about 3–5 cm long and bear winged nutlets about 2–3 mm long.
, Quebec
, northwestern Ontario
, Northern New York State, and New England
. Generally found in northern habitats or high elevations, particularly on moist ground.
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 difference chromosome numbers. The most conclusive method of identification is from chromosome analysis.
Birch
Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...
species native to Eastern Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and the North Eastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Until recently it was considered a variety of Betula papyrifera (Paper Birch), with which it shares many characteristics, and it was classified as B. papyrifera var. cordifolia (Regel) Fern.
Description
Betula cordifolia is a deciduous tree that reaches heights of about 25 m and trunk diameters of about 70 cm. Mature barkBark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
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. The leaves
Leaves
-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...
are alternate, ovate, 6–12 cm long, and double-toothed. As the species epithet suggests, the leaf base is generally cordate (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 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. The flowers are catkins, with pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
catkins 2–4 cm long and seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
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 CanadaAtlantic Canada
Atlantic Canada is the region of Canada comprising the four provinces located on the Atlantic coast, excluding Quebec: the three Maritime provinces – New Brunswick, Prince Edward Island, and Nova Scotia – and Newfoundland and Labrador...
, Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
, northwestern Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, Northern New York State, and New England
New England
New England is a region in the northeastern corner of the United States consisting of the six states of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut...
. Generally found in northern habitats or high elevations, particularly on moist ground.
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 difference chromosome numbers. The most conclusive method of identification is from chromosome analysis.