''Sterculia urens'' is a species of
plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
in the family
Malvaceae
Malvaceae, or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of economic importance include okra, cotton, cacao and durian. There are also some genera containing familiar ...
. It is native to India and has been introduced into Burma. A small to medium-sized tree with a pale-coloured trunk, it is commonly known as the ''bhutyā'' (
भुत्या) in
Marathi
Marathi may refer to:
*Marathi people, an Indo-Aryan ethnolinguistic group of Maharashtra, India
*Marathi language, the Indo-Aryan language spoken by the Marathi people
*Palaiosouda, also known as Marathi, a small island in Greece
See also
*
* ...
(meaning "ghost tree"), kulu, Indian tragacanth, gum karaya, katira, sterculia gum or kateera gum.
The
specific name ''urens'' refers to the stinging hairs present on the flowers.
Subspecies
''Sterculia urens'' var. ''thorelii''
(Pierre) C. Phengklai is an accepted name according to the
Catalogue of Life
The Catalogue of Life is an online database that provides an index of known species of animals, plants, fungi, and microorganisms. It was created in 2001 as a partnership between the global Species 2000 and the American Integrated Taxonomic Info ...
and found in
Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
, where it is known as ''bảy thưa Thorel''.
Synonym
A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...
s of ''S.u. thorelii'' are: ''Sterculia thorelii''
Pierre
Pierre is a masculine given name. It is a French form of the name Peter. Pierre originally meant "rock" or "stone" in French (derived from the Greek word πέτρος (''petros'') meaning "stone, rock", via Latin "petra"). It is a translation ...
and ''Clompanus thorellii''
Kuntze.
Description
The gum karaya is a medium-sized
deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...
tree with horizontally-spreading branches, growing to a maximum height of about . The bark is smooth, fibrous and thick, greenish-grey, with the surface layer peeling off in large flakes. The twigs are hairy at first. The leaves are alternate, simple, hairy beneath and have three to five palmate lobes. They are clustered at the tips of the twigs.
;Flowers
![Sterculia urens 1](https://upload.wikimedia.org/wikipedia/commons/3/36/Sterculia_urens_1.jpg)
The flowers are yellowish-green and produced in panicles in the axils of the leaves. They are polygamous (having male, female and bisexual flowers on the same tree) and are clad in sticky or glandular short hairs. The calyx has five lobes and there are no petals. Male flowers have a columnar boss of ten stamens while bisexual flowers have a ring of anthers round the five free, radiating carpels which grow to when fully developed. They are pinkish and densely covered with red hairs, including stinging hairs. ''Apis indica'' is a known pollinator while wind doesn't play any role in pollination.
;Fruits
![Sterculia urens fruits Bengaluru](https://upload.wikimedia.org/wikipedia/commons/f/f2/Sterculia_urens_fruits_Bengaluru.jpg)
They split open when ripe to reveal up to six squarish, brown or black seeds.
Distribution and habitat
The gum karaya is native to the
Indian Subcontinent
The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian O ...
,
Indo-China
Mainland Southeast Asia, also known as the Indochinese Peninsula or Indochina, is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to the west an ...
and
Malesia
Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalayan and Australasian realms, and also a phytogeographical floristic region in the Paleotropical Kingdom. It has been given different definitions. The ...
. It is a common species and grows in deciduous forests, both wet and dry. It is often found on steep, rock-strewn slopes at altitudes between .
[
]
Gallery
File:Sterculia urens W2 IMG 1913.jpg, Foliage and fruit
File:Sterculia urens raigad maharashtra 2.jpg, ''Sterculia urens'' during the summer in Maharashtra
Maharashtra (; , abbr. MH or Maha) is a states and union territories of India, state in the western India, western peninsular region of India occupying a substantial portion of the Deccan Plateau. Maharashtra is the List of states and union te ...
File:Sterculia urens W IMG 1908.jpg
File:Sterculia urens W IMG 1914.jpg
Uses
A natural gum
Natural gums are polysaccharides of natural origin, capable of causing a large increase in a solution's viscosity, even at small concentrations. They are mostly botanical gums, found in the woody elements of plants or in seed coatings.
Human u ...
known as gum karaya
Gum karaya or gum sterculia, also known as Indian gum tragacanth, is a vegetable gum produced as an exudate by trees of the genus ''Sterculia''. Chemically, gum karaya is an acid polysaccharide composed of the sugars galactose, rhamnose and galac ...
is exuded by the tree when the bark is damaged. This valuable substance is traditionally tapped by cutting or peeling back the bark, or by making deep gashes at the base of the trunk with an axe. Such crude methods of extraction often kill the tree, but it has been found that application of the plant growth regulator ethephon
Ethephon is a plant growth regulator.
Mechanism of action
Upon metabolism by the plant, it is converted into ethylene, a potent regulator of plant growth and ripeness. It is also a butyrylcholinesterase inhibitor.
Uses in various crops
Etheph ...
stimulates the production of gum, and when used in carefully controlled amounts, increases gum yield and enhances healing of the wounds.
Karaya gum swells when it absorbs water and is used as a laxative
Laxatives, purgatives, or aperients are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation.
Laxatives vary as to how they work and the side effects they may have. Certain stimulant, lubri ...
because adds bulk to the contents of the intestine, stimulating the gut to expel waste material. Karaya gum is also reputed to have aphrodisiac
An aphrodisiac is a substance that increases sexual desire, sexual attraction, sexual pleasure, or sexual behavior. Substances range from a variety of plants, spices, foods, and synthetic chemicals. Natural aphrodisiacs like cannabis or cocain ...
al properties, but there is insufficient evidence to support this.[ Other uses for the gum are as a thickener in ]cosmetics
Cosmetics are constituted mixtures of chemical compounds derived from either natural sources, or synthetically created ones. Cosmetics have various purposes. Those designed for personal care and skin care can be used to cleanse or protect ...
and medications
A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and rel ...
, and as an adhesive for dentures
Dentures (also known as false teeth) are prosthetic devices constructed to replace missing teeth, and are supported by the surrounding soft and hard tissues of the oral cavity. Conventional dentures are removable (removable partial denture or ...
. In manufacturing, it is added as a binder, emulsifier and stabiliser in the preparation of beverages and foods. The seeds are roasted and eaten.[
]
References
External links
*
*
{{taxonbar, from=Q3498736
urens
Flora of India (region)
Flora of Indo-China
Trees of Vietnam