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Eusideroxylon zwageri Teijsm. & Binn.
| Family Name: | Lauraceae |
| Common Name: | Borneo Ironwood, Billian, Ironwood, Ulin, Belian |
Eusideroxylon zwageri produces hard and durable timber, giving it the common name Ironwood. The timber is used for heavy construction and building of traditional houses in Borneo. Tools used to saw the wood may become blunt very quickly due to the hardness of the wood.
Name
Classifications and Characteristics
| Plant Division | Angiosperms (Flowering Seed Plants) |
|---|---|
| Plant Growth Form | Tree |
| Maximum Height | 50 m |
Biogeography
| Native Distribution | Borneo |
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| Native Habitat | Terrestrial |
| Preferred Climate Zone | Tropical |
| Local Conservation Status | Non-native |
Description and Ethnobotany
| Growth Form | It is a tree, up to 50 m tall, with buttress up to 220 cm in diameter. Bark is grey-brown and flakes off as small subquadrangular pieces. |
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| Foliage | Leaves are elliptic to ovate (14 – 18 cm long and 5 – 11 cm wide), leathery with rounded to subcordate leaf base, obtuse to shortly acuminate leaf tip and entire leaf margin. The upper side of the leaves is smooth and hairless, while the underside of the leaves may have hairs present on the larger veins. Petiole is about 0.6 – 1.5 cm long. |
| Flowers | Flowers occur in a dense and drooping cluster (about 10 – 20 cm long) at the axillary position. Flower is greenish, yellow or purplish, radially symmetrical and consists of a shallow flower tube. In addition, it has 6 tepals arranged in 2 whorls, 6 glandless staminodia arranged in whorls, 3 fertile stamens without glands, and a disc-like stigma. |
| Fruit | Occurring in 1 or 2 in each panicle, the fruit is an elliptical or oval shaped drupe (about 7 – 16 cm long and 5 – 9 cm wide) and turning shiny black when mature. Each fruit contains one large seed which has a hard and furrowed seed coat. |
| Cultivation | Young seedlings thrive in semi-shaded conditions and require full sun as they grow older. |
| Etymology | Eusideroxylon, in greek, means iron wood, which refers to the hard timber. The species epithet is named after J. Zwager (1824-1864), a Dutch plant collector who sent specimens to Buitenzorg Botanic Garden. |
| Ethnobotanical Uses | Timber & Products: The timber is known as Ulin. The wood is heavy, hard, and durable, so it is often used for marine construction such as ships and wharfs, and heavy construction such as bridges, power line poles and houses. The indigenous people (Dayak) in Borneo also used the timber to build traditional houses known as longhouses. Tools used to saw the wood may become blunt very quickly due to the hardness of the wood. |
Plant Care and Propagation
| Light Preference | Full Sun |
|---|---|
| Water Preference | Moderate Water |
| Plant Growth Rate | Moderate |
Foliar
| Mature Foliage Colour(s) | Green, Red |
|---|---|
| Leaf Area Index (LAI) for Green Plot Ratio | 3.0 (Tree - Intermediate Canopy) |
References
| References | Kostermans, A.J.G.H. (1957). Lauraceae. Reinwardtia 4: 193–256 |
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Image Repository
Others
| Master ID | 1598 |
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| Species ID | 2891 |
| Flora Disclaimer | The information in this website has been compiled from reliable sources, such as reference works on medicinal plants. It is not a substitute for medical advice or treatment and NParks does not purport to provide any medical advice. Readers should always consult his/her physician before using or consuming a plant for medicinal purposes. |