''Dillenia indica'', commonly known as elephant apple or Ou Tenga, is a species of ''

Dillenia ''Dillenia'' is a genus of flowering plants in the family Dilleniaceae, native to tropical and subtropical regions of southern Asia, Australasia, and the Indian Ocean islands. The genus is named after the German botanist Johann Jacob Dillenius, ...

'' native to China and tropical Asia. Albinistic Dillenia indica in Pakke Tiger Reserve

Description

It is an

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

large

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

or small to medium-sized tree growing to 15 m tall. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are 15–36 cm long, with a conspicuously corrugated surface with impressed veins. Its branches are used to make good firewood. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s are large, 15–20 cm diameter, with five white petals and numerous yellow stamens. Its characteristic round fruits are large, greenish yellow, have many seeds and are edible. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

is a 5–12 cm diameter aggregate of 15 carpels, each

carpel Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

containing five seeds embedded in an edible but fibrous pulp.Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan .Flora of Pakistan
''Dillenia indica''
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Taxonomy

''Dillenia indica'' was one of the many species first described by

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

in the 10th edition of his ''

Systema Naturae ' (originally in Latin written ' with the ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial nomen ...

'' in 1759.

Ecology

''Dillenia indica'' produces a large hard edible fruit which is accessible only to the

megaherbivore Megaherbivores (Greek μέγας megas "large" and Latin ''herbivora'' "herbivore") are large terrestrial herbivores that can exceed in weight. This polyphyletic group of megafauna includes elephants, rhinos, hippos, and giraffes. The largest ...

s in the wild. A study in the

Buxa Tiger Reserve , photo = Buxa Tiger Reserve forest 2014.jpg , iucn_category = II , map = India West Bengal , map_width = , label = Buxa NP , label_position = right , location = West Bengal, India , nearest_city = Alipurduar , coordinates = , area_km ...

by ecologists Sekar & Sukumar has shown that

Asian elephants The Asian elephant (''Elephas maximus''), also known as the Asiatic elephant, is the only living species of the genus '' Elephas'' and is distributed throughout the Indian subcontinent and Southeast Asia, from India in the west, Nepal in the n ...

appear to have a particular fondness for the fruits of ''D. indica'', and are hence an important seed disperser for this tree. With the prospect of

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

of the elephants this tree has developed a back-up system, whereby its hard fruits that were only accessible to megaherbivores, slowly soften on the forest floor through the dry season to allow access to successively smaller animals such as

macaque The macaques () constitute a genus (''Macaca'') of gregarious Old World monkeys of the subfamily Cercopithecinae. The 23 species of macaques inhabit ranges throughout Asia, North Africa, and (in one instance) Gibraltar. Macaques are principally ...

rodents Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are nat ...

and

squirrels Squirrels are members of the family (biology), family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flyi ...

. Seeds from both old and soft fruits are able to

germinate Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...

well, enabling the persistence of this tree to be independent of the survival of its major megaherbivore disperser.

Uses

The fruit pulp is sour and used in

Indian cuisine Indian cuisine consists of a variety of regional and traditional cuisines native to India. Given the diversity in soil, climate, culture, ethnic groups, and occupations, these cuisines vary substantially and use locally available spices, he ...

in curries, jam (

ouu khatta ''Ou Khatta'' () is a sweet and sour chutney or marmalade made of ''ou'' (elephant apple; ''Dillenia indica'') in jaggery, in the Indian state of Odisha, mostly in post- monsoon season. Sometimes ''ou'' is added to ''dal'' or '' dalma''. It is ...

), and jellies. Because it is a main source of food for elephants, monkeys and

deer Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...

, collection of fruit from the core areas of the forest is prohibited. Commercial sale of the fruit is also prohibited, in an effort to help keep the food-chain system of the forest from dismantling totally. Dillenia indica Flower

References

{{Taxonbar, from=Q48334 indica Trees of China Flora of tropical Asia Plants described in 1753 Taxa named by Carl Linnaeus