Buttress roots, also known as plank roots or stilt roots, are large, wide

root In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...

s on all sides of a shallowly rooted

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

. Typically, they are found in nutrient-poor

tropical forest Tropical forests are forested ecoregions with tropical climates – that is, land areas approximately bounded by the Tropic of Cancer, tropics of Cancer and Tropic of Capricorn, Capricorn, but possibly affected by other factors such as prevailing ...

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

s that may not be very deep. They may prevent the tree from falling over (hence the name

buttress A buttress is an architectural structure built against or projecting from a wall which serves to support or reinforce the wall. Buttresses are fairly common on more ancient (typically Gothic) buildings, as a means of providing support to act ...

). Buttresses are tension elements, being larger on the side away from the stress of asymmetrical canopies. The roots may intertwine with buttress roots from other trees and create an intricate mesh, which may help support trees surrounding it. They can grow up to tall, spread for above the soil, and then continue another 100 feet below. When the roots spread horizontally, they are able to cover a wider area for collecting nutrients. They stay near the upper soil layer because all the main nutrients are found there. Buttress roots vary greatly in size from barely discernable to many square yards (square meters) of surface. The largest for which there is photographic evidence is a Moreton Bay Fig (''

Ficus macrophylla ''Ficus macrophylla'', commonly known as the Moreton Bay fig or Australian banyan, is a large evergreen banyan tree of the mulberry and fig family Moraceae. It is native to eastern Australia, from the Wide Bay–Burnett region of Queensland i ...

'') at Fig Tree Pocket (an outlying district of

Brisbane Brisbane ( ; ) is the List of Australian capital cities, capital and largest city of the States and territories of Australia, state of Queensland and the list of cities in Australia by population, third-most populous city in Australia, with a ...

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

) which was photographed in 1866 with an adult man. The buttresses were long and in height. Halfway out the buttress is twice the height of the man. The tree died in 1893 from flood damage. The tallest buttresses are those of '' Huberodendron'' (Bombacaceae) of the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

which extend up to up a tree about in height. The most extensive buttresses are those of the Kapok, or Silk Cotton Tree (''

Ceiba pentandra ''Ceiba pentandra'' is a tropical tree of the order (biology), order Malvales and the family (biology), family Malvaceae (previously emplaced in the family Bombacaceae), native to Mexico, Central America and the Caribbean, northern South America, ...

''), of the

Neotropics The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeog ...

and tropical Africa. The buttresses can extend outwards as much as from the tree as buttresses, then continue as superficial roots for a total of .

Notable and historic specimen trees with buttress roots

* ''

'' of

Vieques, Puerto Rico Vieques (; ), officially Isla de Vieques, is an island, Culebra barrio-pueblo, town and Municipalities of Puerto Rico, municipality of Puerto Rico, and together with Culebra, Puerto Rico, Culebra, it is geographically part of the Spanish Virgin ...

* Moreton Bay fig (''

'') in Queensland, Australia *

Jackfruit The jackfruit or ''nangka'' (''Artocarpus heterophyllus'') is a species of tree in the Common fig, fig, mulberry, and breadfruit family (Moraceae). The jackfruit is the largest tree fruit, reaching as much as in weight, in length, and in d ...

(''Artocarpus heterophyllus''), India * ''

Terminalia arjuna ''Terminalia arjuna'' is a tree of the genus '' Terminalia''. It is commonly known as arjuna or arjun tree in English. It is used as a traditional medicinal plant. Description ''T. arjuna'' grows to about 20–25 metres tall; usually has a buttr ...

'', India * '' Koompassia excelsa'', Southeast Asia

Gallery

File:Buttress roots. Jensen's Crossing near Cooktown, Australia. 1988.jpg, Buttress roots. Jensen's Crossing near Cooktown, Australia. 1988 File:Terminalia arjuna trunk 03 by Line1.JPG, Buttress roots of ''

'' File:Buttress root system..jpg, A buttress root system provides structural support. File:CeibaTreePeru02.jpg, Buttress roots of an especially large ''

Ceiba ''Ceiba'' is a genus of trees in the family Malvaceae, native to Tropics, tropical and Subtropics, subtropical areas of the Americas (from Mexico and the Caribbean to northern Argentina) and tropical West Africa. Some species can grow to tall ...

'' tree near shore of Amazon River, close to Iquitos, Peru File:Koompassia excelsa.png, The large buttress roots of '' Koompassia excelsa''

References

{{commons Plant roots Trees