''Betula murrayana'' commonly known as Murray birch, is a

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

species of small

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 3 ...

that is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Washtenaw County, Michigan Washtenaw County ( ) is a County (United States), county located in the U.S. state of Michigan. At the United States 2020 Census, 2020 census, the population was 372,258. The county seat and largest city is Ann Arbor, Michigan, Ann Arbor. The ...

in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

and St. Williams, Norfolk County,

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

, in

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

Description

The tree can be up to 15 meters in height and usually has several trunks. The bark of the mature trees is usually dark red-reddish brown and has horizontally-expanded

lenticel A lenticel is a porous tissue consisting of cells with large intercellular spaces in the periderm of the secondarily thickened organs and the Bark (botany), bark of woody stems and roots of gymnosperms and dicotyledonous flowering plants. It func ...

s. Its leaves are 5–11 centimeters × 3–6 centimeters.

Taxonomy

It was named by Burton V. Barnes and Bruce P. Dancik, in ''Canadian Journal of Botany'' 63(2):223-226, in 1985. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

honors Frank Murray, the person who discovered the Michigan population of the species. ''Betula murrayana'' is an evolutionarily recent species that arose through hybridization between ''

Betula alleghaniensis ''Betula alleghaniensis'', the yellow birch, golden birch, or swamp birch, is a large tree and an important lumber species of birch native to northeastern North America. Its vernacular names refer to the golden color of the tree's bark. In the pa ...

'' and another hybrid, ''Betula'' × ''purpusii'' (a hybrid of ''B. alleghaniensis'' and '' Betula pumila''). ''Betula murryana'' has a chromosome number of 2n=112, while ''B. alleghaniensis'' has 2n=84, ''B. pumila'' has 2n=56. and ''B.'' × ''purpusii'' has 2n=70.

Conservation

Only two sites are known. The Ontario population has not been re-located, despite searches, and its status is unclear. The Michigan population has only one surviving non-cultivated individual. However future populations may be discovered along the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes spanning the Canada–United States border. The five lakes are Lake Superior, Superior, Lake Michigan, Michigan, Lake Huron, H ...

St. Lawrence Valley The St. Lawrence River (, ) is a large international river in the middle latitudes of North America connecting the Great Lakes to the North Atlantic Ocean. Its waters flow in a northeasterly direction from Lake Ontario to the Gulf of St. Lawren ...

, as there are many areas where the parent species overlap, and the species is a natural hybrid. The

Holden Arboretum The Holden Arboretum, in Kirtland, Ohio, is one of the largest arboreta and botanical gardens in the United States, with more than , including devoted to collections and gardens. Diverse natural areas and ecologically sensitive habitats make u ...

, the

University of Michigan The University of Michigan (U-M, U of M, or Michigan) is a public university, public research university in Ann Arbor, Michigan, United States. Founded in 1817, it is the oldest institution of higher education in the state. The University of Mi ...

, and Matthaei Botanical Gardens all have propagated seedlings from cuts of the Michigan individual, which could be used to conserve this species if it is faced with

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

References

murrayana Flora of Michigan Flora of Ontario {{Fagales-stub