''Engelhardia rigida'' is a tree in the family

Juglandaceae The Juglandaceae are a plant family known as the walnut family. They are trees, or sometimes shrubs, in the order Fagales. Members of this family are native to the Americas, Eurasia, and Southeast Asia. The nine or ten genera in the family have ...

. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''rigida'' means 'stiff', referring to the leaves.

Description

''Engelhardia rigida'' grows up to tall, with a trunk diameter of up to . It has

buttresses 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 a ...

up to high and extending out to . The bark is reddish to grey. The papery leaves are

elliptic In mathematics, an ellipse is a plane curve surrounding two focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant. It generalizes a circle, which is the special type of ellipse in ...

ovate Ovate may refer to: * Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe * Ovates, one of three ranks of membership in the Welsh Gorsedd * Vates or ovate, a term for ancient Celtic bards ...

and measure up to long, occasionally to long. The fruits are winged. The tree is sometimes harvested for its timber in

Papua New Guinea Papua New Guinea, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...

Distribution and habitat

''Engelhardia rigida'' is native to

Borneo Borneo () is the List of islands by area, third-largest island in the world, with an area of , and population of 23,053,723 (2020 national censuses). Situated at the geographic centre of Maritime Southeast Asia, it is one of the Greater Sunda ...

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

Sulawesi Sulawesi ( ), also known as Celebes ( ), is an island in Indonesia. One of the four Greater Sunda Islands, and the List of islands by area, world's 11th-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Min ...

, the

Maluku Islands The Maluku Islands ( ; , ) or the Moluccas ( ; ) are an archipelago in the eastern part of Indonesia. Tectonics, Tectonically they are located on the Halmahera Plate within the Molucca Sea Collision Zone. Geographically they are located in West ...

, the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

and

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

. Its habitat is mixed

dipterocarp Dipterocarpaceae is a family of flowering plants with 22 genera and about 695 known species of mainly lowland tropical forest trees. Their distribution is pantropical, from northern South America to Africa, the Seychelles, India, Indochina, Indo ...

forests, to elevations of . It is threatened by conversion of its habitat for urban development and agriculture.

References

rigida Flora of Borneo Flora of Java Flora of Sulawesi Flora of the Maluku Islands Flora of the Philippines Flora of New Guinea Plants described in 1826 Taxa named by Carl Ludwig Blume {{Fagales-stub