Flora of the United States

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The native flora of the United States includes about 17,000 species of vascular plants, plus tens of thousands of additional species of other plants and plant-like organisms such as algae, lichens 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.[ citation needed ]

Contents

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 southern part of Florida is tropical, as well as Hawaii (including high mountains), and the U.S. territories in the Caribbean and the Pacific, 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. There are also rainforests as well as some of the driest deserts in the world.

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 pecans, 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.

Divisions

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 provinces, characterized by a certain degree of endemism:

Holarctic Kingdom
Circumboreal crack ]
Arctic Province
Canadian Province
North American Atlantic Region
Appalachian Province
Atlantic and Gulf Coastal Plain Province
North American Prairies Province
Rocky Mountain Region
Vancouverian Province
Rocky Mountain Province
Madrean Region
Great Basin Province
Californian Province
Sonoran Province
Neotropical Kingdom
Caribbean Region
West Indian Province
Paleotropic Kingdom
Hawaiian Region
Hawaiian Province

Some prominent botanists who have studied and published on U.S. flora

Further reading

Related Research Articles

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<span class="mw-page-title-main">Neotropical realm</span> One of Earths eight biogeographic realms

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<span class="mw-page-title-main">Antarctic flora</span> Distinct community of plants which evolved on the supercontinent of Gondwana

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<span class="mw-page-title-main">Ecology of California</span> Environments and natural history of California

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<span class="mw-page-title-main">Boreal Kingdom</span> Floristic kingdom in northern Eurasia and the Americas

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<span class="mw-page-title-main">California Floristic Province</span> Region of uniform plant variety in the western United States and Mexico

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<span class="mw-page-title-main">Cape Floristic Region</span> Smallest of the six recognised floral kingdoms of the world

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<span class="mw-page-title-main">North American Atlantic Region</span> Floristic region in the Holarctic kingdom

North 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. It is bordered by the Circumboreal floristic region in the north, by the Rocky Mountain and Madrean floristic regions in the west and by the Caribbean floristic region of the Neotropical Kingdom in the south of Florida. The flora of the region comprises two endemic monotypic families, Hydrastidaceae and Leitneriaceae, and is characterized by about a hundred of endemic genera. The degree of species endemism is very high, many species are Tertiary relicts, which survived the Wisconsin glaciation and are now concentrated in the Appalachians and the Ozarks. A number of genera are shared only with the Canadian floristic province of the Circumboreal region. Moreover, as has long been noted, a large number of relict genera are shared with the relatively distant Eastern Asiatic Region and sometimes Southeast Asia. R. F. Thorne counted at least 74 genera restricted to eastern North America and Asia. The fossil record indicates that during the Tertiary period a warm temperate zone extended across much of the Northern Hemisphere, linking America to Asia.

<span class="mw-page-title-main">Antarctic Floristic Kingdom</span> Geographic area with a relatively uniform composition of plant species in the Antarctic

The Antarctic Floristic Kingdom, also the Holantarctic Kingdom, is a floristic kingdom that includes most areas of the world south of 40°S latitude. It was first identified by botanist Ronald Good, and later by Armen Takhtajan. The Antarctic Floristic Kingdom is a classification in phytogeography, different from the Antarctic realm classification in biogeography, and from Antarctic flora genera/species classifications in botany.

<span class="mw-page-title-main">Eastern Asiatic Region</span> Floristic region in East Asia

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<span class="mw-page-title-main">Rocky Mountain Floristic Region</span>

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<span class="mw-page-title-main">Madrean Region</span> Floristic region in the Holarctic Kingdom

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<span class="mw-page-title-main">Circumboreal Region</span> Floristic region in Eurasia and North America

The Circumboreal Region in phytogeography 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.

<span class="mw-page-title-main">Paleotropical Kingdom</span> One of the Earths six floristic kingdoms

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