Flora of the United States
Encyclopedia
The native
flora
of the United States
includes about 17,000 species
of vascular plants, plus tens of thousands of additional species of other plant
s and plant-like organisms such as algae, lichen
s and other fungi, and mosses. About 3,800 additional non-native species of vascular plants are recorded as established outside of cultivation in the U.S., as well as a much smaller number of non-native non-vascular plants and plant relatives. The United States possesses one of the most diverse temperate floras in the world, comparable only to that of China
.
Several biogeographic
factors contribute to the richness and diversity of the U.S. flora. While most of the United States has a temperate
climate
, Alaska
has vast arctic
areas, the southernmost part of Florida
is subtropical to tropical, Hawaii
is fully tropical (including high mountains), and alpine summits are present on many western mountains, as well as a few in the Northeast. The U.S. coastline borders three oceans: The Atlantic
(and Gulf of Mexico
), the Arctic
, and the Pacific
. Finally, the U.S. shares long borders with Canada
and Mexico
, and is relatively close to the Bahamas, Cuba
and other Caribbean
islands, and easternmost Asia
.
The native flora of the United States has provided the world with a large number of horticultural
and agricultural
plants, mostly ornamentals, such as flowering dogwood
, redbud, mountain laurel, bald cypress, southern magnolia
, and black locust
, all now cultivated in temperate regions worldwide, but also various food plants such as blueberries
, black raspberries
, cranberries
, maple syrup and sugar
, and pecan
s, and Monterey pine
and other timber trees.
Some of the native U.S. plants, such as Franklinia alatamaha, have demonstrably become extinct or extinct in the wild
; others, such as Micranthemum micranthemoides, have not been seen in decades, but may still be extant. Thousands of other native U.S. vascular plants are considered rare, threatened, or endangered, either globally (rangewide) or within particular states.
According to Armen Takhtajan
, Robert F. Thorne, and other geobotanists, the territory of the United States
(including Hawaii
and Alaska
) is divided between three floristic kingdoms, six floristic regions and twelve floristic province
s, characterized by a certain degree of endemism:
Indigenous (ecology)
In biogeography, a species is defined as native to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention. Every natural organism has its own natural range of distribution in which it is regarded as native...
flora
Flora
Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animals is fauna.-Etymology:...
of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
includes about 17,000 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of vascular plants, plus tens of thousands of additional species of other plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s and plant-like organisms such as algae, lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s and other fungi, and mosses. About 3,800 additional non-native species of vascular plants are recorded as established outside of cultivation in the U.S., as well as a much smaller number of non-native non-vascular plants and plant relatives. The United States possesses one of the most diverse temperate floras in the world, comparable only to that of China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
.
Several biogeographic
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
factors contribute to the richness and diversity of the U.S. flora. While most of the United States has a temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
, Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
has vast arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...
areas, the southernmost part of Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
is subtropical to tropical, Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
is fully tropical (including high mountains), and alpine summits are present on many western mountains, as well as a few in the Northeast. The U.S. coastline borders three oceans: The Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
(and Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
), the Arctic
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
, and the Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
. Finally, the U.S. shares long borders with 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 Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and is relatively close to the Bahamas, Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
and other Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
islands, and easternmost Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
.
The native flora of the United States has provided the world with a large number of horticultural
Horticulture
Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...
and agricultural
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
plants, mostly ornamentals, such as flowering dogwood
Flowering Dogwood
Cornus florida is a species of dogwood native to eastern North America, from southern Maine west to southern Ontario, Illinois, and eastern Kansas, and south to northern Florida and eastern Texas, with a disjunct population in Nuevo León and Veracruz in eastern Mexico.-Classification:The flowering...
, redbud, mountain laurel, bald cypress, southern magnolia
Southern magnolia
Magnolia grandiflora, commonly known as the southern magnolia or bull bay, is a tree of the family Magnoliaceae native to the southeastern United States, from coastal Virginia south to central Florida, and west to eastern Texas and Oklahoma...
, and black locust
Black locust
Robinia pseudoacacia, commonly known as the Black Locust, is a tree in the subfamily Faboideae of the pea family Fabaceae. It is native to the southeastern United States, but has been widely planted and naturalized elsewhere in temperate North America, Europe, Southern Africa and Asia and is...
, all now cultivated in temperate regions worldwide, but also various food plants such as blueberries
Blueberry
Blueberries are flowering plants of the genus Vaccinium with dark-blue berries and are perennial...
, black raspberries
Raspberry
The raspberry or hindberry is the edible fruit of a multitude of plant species in the genus Rubus, most of which are in the subgenus Idaeobatus; the name also applies to these plants themselves...
, cranberries
Cranberry
Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus Oxycoccus of the genus Vaccinium. In some methods of classification, Oxycoccus is regarded as a genus in its own right...
, maple syrup and sugar
Maple sugar
Maple sugar is a traditional sweetener in the northeastern United States and Canada, prepared from the sap of the sugar maple tree.-Preparation:...
, and pecan
Pecan
The pecan , Carya illinoinensis, is a species of hickory, native to south-central North America, in Mexico from Coahuila south to Jalisco and Veracruz, in the United States from southern Iowa, Illinois, Missouri, and Indiana east to western Kentucky, southwestern Ohio, North Carolina, South...
s, and Monterey pine
Monterey Pine
The Monterey Pine, Pinus radiata, family Pinaceae, also known as the Insignis Pine or Radiata Pine is a species of pine native to the Central Coast of California....
and other timber trees.
Some of the native U.S. plants, such as Franklinia alatamaha, have demonstrably become extinct or extinct in the wild
Extinct in the Wild
Extinct in the Wild is a conservation status assigned to species or lower taxa, the only known living members of which are being kept in captivity or as a naturalized population outside its historic range.-Examples:...
; others, such as Micranthemum micranthemoides, have not been seen in decades, but may still be extant. Thousands of other native U.S. vascular plants are considered rare, threatened, or endangered, either globally (rangewide) or within particular states.
According to Armen Takhtajan
Armen Takhtajan
Armen Leonovich Takhtajan or Takhtajian , was a Soviet-Armenian botanist, one of the most important figures in 20th century plant evolution and systematics and biogeography. His other interests included morphology of flowering plants, paleobotany, and the flora of the Caucasus...
, Robert F. Thorne, and other geobotanists, the territory of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
(including Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
and Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
) is divided between three floristic kingdoms, six floristic regions and twelve floristic province
Floristic province
A phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phytochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both regions overlap...
s, characterized by a certain degree of endemism:
- Holarctic Kingdom
- Circumboreal RegionCircumboreal RegionThe Circumboreal Region is a floristic region within the Holarctic Kingdom in Eurasia and North America, as delineated by such geobotanists as Josias Braun-Blanquet and Armen Takhtajan....
- Arctic Province
- Canadian Province
- North American Atlantic RegionNorth American Atlantic RegionNorth American Atlantic Region is a floristic region within the Holarctic Kingdom identified by Armen Takhtajan and Robert F. Thorne, spanning from the Atlantic and Gulf coasts to the Great Plains and comprising a major part of the United States and southeastern portions of Canada...
- Appalachian Province
- Atlantic and Gulf Coastal Plain Province
- North American Prairies Province
- Rocky Mountain RegionRocky Mountain RegionThe Rocky Mountain Floristic Region, also known as the Rocky Mountain Floristic Province, is a floristic region within the Holarctic Kingdom in western North America delineated by Armen Takhtajan and Robert F...
- Vancouverian Province
- Rocky Mountain Province
- Madrean RegionMadrean RegionThe Madrean Region is a floristic region within the Holarctic Kingdom in North America, as delineated by Armen Takhtajan and Robert F. Thorne...
- Great Basin ProvinceGreat Basin ProvinceThe Great Basin Province is a region of the Boreal Kingdom that generally corresponds to the Central Basin and Range ecoregion and the Great Basin physiographic section...
- Californian Province
- Sonoran Province
- Great Basin Province
- Circumboreal Region
- Neotropical Kingdom
- Caribbean RegionCaribbean RegionThe Caribbean Region or Caribbean Coast Region is a natural region of Colombia mainly composed of eight Departments located contiguous to the Caribbean. The area covers a total land area of including the San Andres Island Archipelago of San Andrés, Providencia and Santa Catalina in the Caribbean...
- West Indian Province
- Caribbean Region
- Paleotropic Kingdom
- Hawaiian Region
- Hawaiian Province
- Hawaiian Region
Some prominent botanists who have studied and published on U.S. flora
- John ClaytonJohn Clayton (botanist)John Clayton was a Colonial plant collector in Virginia.Clayton was born in England, and moved to Virginia with his father in 1715, where he lived in Gloucester County, near the Chesapeake Bay, exploring the region botanically. Clayton sent many specimens, as well as manuscript descriptions, to...
(1694–1773) - John BartramJohn Bartram*Hoffmann, Nancy E. and John C. Van Horne, eds., America’s Curious Botanist: A Tercentennial Reappraisal of John Bartram 1699-1777. Memoirs of the American Philosophical Society, vol. 243. ....
(1699–1777) - Carl Linnaeus (1707–1778)
- Peter Kalm (1716–1779)
- William BartramWilliam BartramWilliam Bartram was an American naturalist. The son of Ann and John Bartram, William Bartram and his twin sister Elizabeth were born in Kingsessing, Pennsylvania, near Philadelphia. As a boy, he accompanied his father on many of his travels, to the Catskill Mountains, the New Jersey Pine Barrens,...
(1739–1823) - André MichauxAndré MichauxAndré Michaux was a French botanist and explorer.-Biography:Michaux was born in Satory, now part of Versailles, Yvelines. After the death of his wife within a year of their marriage he took up the study of botany and was a student of Bernard de Jussieu...
(1746–1802) - William Clark (1770–1838)
- Meriwether LewisMeriwether LewisMeriwether Lewis was an American explorer, soldier, and public administrator, best known for his role as the leader of the Lewis and Clark Expedition also known as the Corps of Discovery, with William Clark...
(1774–1809) - Frederick Traugott PurshFrederick Traugott PurshFrederick Traugott Pursh was a German-American botanist.Born in Grossenhain, Saxony, to the name Friedrich Traugott Pursh, he was educated at Dresden Botanical Gardens, and emigrated to the United States in 1799...
(1774–1820) - Alphonse Louis Pierre Pyramus de Candolle (1778–1841)
- Constantine Samuel Rafinesque (1783–1840)
- Thomas NuttallThomas NuttallThomas Nuttall was an English botanist and zoologist, who lived and worked in America from 1808 until 1841....
(1786–1859) - John Torrey (1796–1873)
- George EngelmannGeorge EngelmannGeorge Engelmann, also known as Georg Engelmann, was a German-American botanist. He was instrumental in describing the flora of the west of North America, then very poorly-known; he was particularly active in the Rocky Mountains and northern Mexico.-Origins:George Engelmann was born in Frankfurt...
(1809–1884) - Asa GrayAsa Gray-References:*Asa Gray. Dictionary of American Biography. American Council of Learned Societies, 1928–1936.*Asa Gray. Encyclopedia of World Biography, 2nd ed. 17 Vols. Gale Research, 1998.*Asa Gray. Plant Sciences. 4 vols. Macmillan Reference USA, 2001....
(1810–1888) - George VaseyGeorge Vasey (botanist)George S. Vasey was an English-born American botanist who collected a lot in Illinois before integrating the United States Department of Agriculture , where he became Chief Botanist and curator of the greatly expanded National Herbarium.-Biography:George Vasey was born in 1822 in Snainton near...
(1822–1893) - Sereno WatsonSereno WatsonSereno Watson was an American botanist.Graduating from Yale in 1847, he drifted through various occupations until, in California, he joined the Clarence King Expedition and eventually became its expedition botanist...
(1826–1892) - Charles Sprague SargentCharles Sprague SargentCharles Sprague Sargent was an American botanist. He was the first director of the Arnold Arboretum at Harvard University in Boston, Massachusetts and the standard botanical author abbreviation Sarg. is applied to plants he described.-Biography:Sargent was the second son of Henrietta and...
(1841–1927) - Edward Lee GreeneEdward Lee GreeneEdward Lee Greene, Ph.D., was an American botanist known for his numerous publications including the two-part Landmarks of Botanical History and the naming or redescribing of over 4,400 species of plants in the American West.- Early Life :Edward Lee Greene was born on August 20, 1843 in...
(1843–1915) - John Merle CoulterJohn Merle CoulterJohn Merle Coulter, Ph. D. was an American botanist and educator, brother of Stanley Coulter, born at Ningpo, China. He received his education at Hanover College in Indiana. He served in the Rocky Mountains for two years as botanist to the United States Geological Survey...
(1851–1928) - Marcus Eugene Jones (1852–1934)
- Liberty Hyde BaileyLiberty Hyde BaileyLiberty Hyde Bailey was an American horticulturist, botanist and cofounder of the American Society for Horticultural Science.-Biography:...
(1858–1954) - Nathaniel Lord BrittonNathaniel Lord BrittonNathaniel Lord Britton was an American botanist and taxonomist who founded the New York Botanical Garden in the Bronx, New York. Britton was born in New Dorp in Staten Island, New York...
(1859–1934) - Aven Nelson (1859–1952)
- Per Axel RydbergPer Axel RydbergPer Axel Rydberg was a Swedish-born, American botanist who was the first curator of the New York Botanical Garden Herbarium. -Biography:...
(1860–1931) - Alfred RehderAlfred RehderAlfred Rehder was a horticulturist and taxonomist who worked at the Arnold Arboretum of Harvard University. Rehder was a newspaper writer from Germany who was originally hired as a laborer at the Arnold Arboretum. His talents for horticultural plant taxonomy were soon recognized, however...
(1863–1949) - Albert Spear Hitchcock (1865–1935)
- Charles PiperCharles PiperCharles Vancouver Piper was an American botanist and agriculturalist. Born in Victoria, British Columbia, Canada, he spent his youth in Seattle, Washington Territory and graduated from the University of Washington Territory in 1885. He taught botany and zoology in 1892 at the Washington...
(1867–1926) - Willis Lynn Jepson (1867–1946)
- John Kunkel SmallJohn Kunkel SmallJohn Kunkel Small was an American botanist.He was the first Curator of Museums at The New York Botanical Garden, a post in which he served from 1898 until 1906. From 1906 to 1934 he was Head Curator and then from 1934 until his death he was Chief Research Associate and Curator...
(1869–1938) - Mary Agnes ChaseMary Agnes ChaseMary Agnes Meara Chase was an American botanist. She specialized in the study of grasses and conducted extensive field work in South America, often personally funding her research trips, as it was considered inappropriate for women to conduct such work...
(1869–1963) - Merritt Lyndon FernaldMerritt Lyndon FernaldMerritt Lyndon Fernald was an American botanist. In his time he was regarded as the most respected scholar of the taxonomy and phytogeography of the vascular plant flora of temperate eastern North America. He published more than 850 scientific papers and wrote and edited the seventh and eighth...
(1873–1950) - LeRoy Abrams (1874–1956)
- Henry Allan Gleason (1882–1975)
- Paul Carpenter StandleyPaul Carpenter StandleyPaul Carpenter Standley was an American botanist.Standley was born in Avalon, Missouri...
(1884–1963) - Edgar Theodore Wherry (1885–1982)
- Earl Edward Scherff (1886–1966)
- Emma Lucy BraunEmma Lucy BraunE. Lucy Braun was a prominent botanist, ecologist, and expert on the forests of the eastern United States.- Life :...
(1889–1971) - Philip Alexander Munz (1892–1974)
- Harold St. JohnHarold St. JohnHarold St. John was a professor of botany at the University of Hawaii at Mānoa from 1929 to 1958. A prolific specialist in field botany and systematics, he is credited with discovering about 500 new species of Pandanus, along with many other species, especially in the Pacific Islands.Born in...
(1892–1991) - Eric HulténEric HulténOskar Eric Gunnar Hultén was a Swedish botanist, plant geographer and 20th century explorer of The Arctic. He was born in Halla in Södermanland. He took his licentiate exam 1931 at Stockholm University and obtained his doctorate degree in botany at Lund University in 1937...
(1894–1981) - Ivan Murray JohnstonIvan Murray JohnstonI. M. Johnston , was a United States botanist. He studied at Pomona College in Claremont, California and at Harvard University...
(1898–1960) - Charles Leo Hitchcock (1902–1986)
- Frederick Joseph Hermann (1906–1987)
- George Ledyard Stebbins (1906–2000)
- Elbert Luther Little, Jr. (1907–2004)
- Julian Alfred SteyermarkJulian Alfred SteyermarkJulian Alfred Steyermark was an American botanist. His focus was on New World vegetation, and he specialized in the family Rubiaceae.- Life and work :...
(1909–1988) - Lyman David Benson (1909–1993)
- Reed Clark Rollins (1911–1998)
- Rupert Charles BarnebyRupert Charles BarnebyRupert Charles Barneby was a British-born self-taught botanist whose primary specialty was the Fabaceae , the pea family, but he also worked on Menispermaceae and numerous other groups...
(1911–2000) - Albert Ernest RadfordAlbert Ernest RadfordAlbert Ernest Radford was an American botanist active in the Southeastern United States. He was best known for his work as senior author of Manual of the Vascular Flora of the Carolinas, the definitive flora for North Carolina and South Carolina.-Biography:Radford was born in Augusta, Georgia to...
(1918–2006) - Warren Herbert Wagner (1920–2000)
- William Alfred WeberWilliam Alfred WeberWilliam Alfred Weber was born in 1918. He is Professor Emeritus at the University of Colorado at Boulder, and former curator of the University of Colorado Museum Herbarium.-List of lichens named by William A. Weber:...
(b. 1918) - Arthur CronquistArthur CronquistArthur John Cronquist was a North American botanist and a specialist on Compositae. He is considered one of the most influential botanists of the 20th century, largely due to his formulation of the Cronquist system. Two plant genera in the aster family have been named in his honor...
(1919–1992) - Ronald Leighton McGregor (born 1919)
- Carlyle August Luer (born 1922)
- Robert Kral (born 1926)
- Stanley Larson WelshStanley Larson WelshStanley Larson Welsh is an American botanist. He has worked as professor of integrative biology at the Brigham Young University for 44 years and was the founding curator of that university's herbarium, which is named after him...
(born 1928) - George William Argus (born 1929)
- Edward Groesbeck Voss (born 1929)
- James Lauritz Reveal (born 1941)
- Anton Alfred Reznicek (born 1950)
- Warren Lambert Wagner (born 1950)
- Barbara Jean Ertter (born 1953)
- John Thomas Kartesz
Further reading
- Flora of North America North of Mexico. 12+ vols. New York and Oxford, 1993+.
- The PLANTS Database @ United States Department of AgricultureUnited States Department of AgricultureThe United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...
- NatureServe Explorer