Buttress roots also known as plank roots are large, wide

root In vascular plants, the roots are the 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 below the su ...

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, including only woody plants with secondary growth, plants that are ...

. Typically, they are found in nutrient-poor

tropical forest Tropical forests (a.k.a. jungle) are forested landscapes in tropical regions: ''i.e.'' land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds. Some tropical fore ...

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

s that may not be very deep. They 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 buildings, as a means of providing support to act against the lateral (s ...

) while also gathering more nutrients. 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 and spread for 30 metres above the soil then for another 30 metres 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 family Moraceae native to eastern Australia, from the Wide Bay–Burnett region in the north to the Illawarra in New ...

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

Brisbane Brisbane ( ) is the capital and most populous city of the Australian state of Queensland, and the third-most populous city in Australia and Oceania, with a population of approximately 2.6 million. Brisbane lies at the centre of the South ...

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

) which was photographed in 1866 with an adult man. The buttresses were 40 to 50 feet (12 to 15 meters) long and 35 to 40 feet (11 to 12 meters) in height. Halfway out the buttress is twice the height of the man. It died in 1893 from flood damage. The tallest buttresses are those of ''Huberodendron duckei'' (Bombacaceae) of the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its 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 of Boli ...

which extend up to 70 feet (21 meters) up a tree about 145 feet (44 meters) in height. The most extensive buttresses are those of Kapok, or Silk Cotton Tree (''

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

'') 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 bioge ...

and tropical

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

. The buttresses can extend up to 65 feet (twenty meters) from the tree as buttresses, then continue as superficial roots for a total of 165 feet (fifty meters). Terminalia arjuna trunk 03 by Line1

Notable and historic specimen trees with buttress roots

*''

'' of Vieques, Puerto Rico *Moreton Bay fig (''

'') in Queensland, Australia *

Jackfruit The jackfruit (''Artocarpus heterophyllus''), also known as jack tree, is a species of tree in the fig, mulberry, and breadfruit family ( Moraceae). Its origin is in the region between the Western Ghats of southern India, all of Bangladesh, ...

(''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. Description ''T. arjuna'' grows to about 20–25 metres tall; usually has a buttressed trunk, and forms a wide canopy at t ...

'', India

References

{{commons, Buttress root Plant roots Trees