Belian / Borneo Ironwood

Belian/ Borneo Ironwood

Scientific name: Eusideroxylon zwageri
Family name: Lauraceae

Belian trees in Taman Tugu
The Belian tree is an indigenous rainforest tree that are amongst the 4,100 trees added to the Taman Tugu site, selected in collaboration with Forest Research Institute of Malaysia (“FRIM”) and Malaysian Nature Society (“MNS”). These are one of the trees being added which are classified in ‘Vulnerable’ in the International Union for Conservation of Nature (“IUCN”) Red List of Threatened Species overexploitation and shifting agriculture. These trees are heavily harvested for timber. The timber is one of the hardest and most durable timbers of Southeast Asia.

Physical Features
The Belian tree is slow-growing, evergreen tree that can grow up to 40-50m in height. It takes about 120 years for the tree to reach 30cm diameter. The Belian tree has an elephant-foot like base. The leaves of the tree are in dark-green in colour, the surface is simple and leathery. The shape of the leaf is elliptical to ovate. The inflorescences which are in axils of leaves, include panicles, racemes, compound cymes or prseudoumbels. The flowers are normally yellow to greenish or white in colour. The Belian fruits and seeds are poisonous and dangerous.

The Belian wood is categorised under heavy hardwood group and of high market value. The wood is very hard, does not rot easily and is naturally resistant because of the unique anatomical features, that it is nick-named as “Borneo ironwood”. The stumps of logged Belian trees are still around decades after they were felled. Due to its density, the Belian tree is one of very few wood species that does not float in water. Belian wood is widely used in heavy construction and large-scale production such as for house structures, pillars, floors, and walls. The Belian wood is also made into shingles for roofing. Dayak longhouse structure is usually built using Belian wood due to its high resistances from water and insert attack. It is also valued highly as coffin wood by the Chinese.

These trees grow in lowland areas of primary forest from around sea level to elevations of 400 metres, in flat or sloping terrain, and also occurs in old secondary forest. It is also found along the riverbanks. These trees are native to Malaysia, Indonesia, and the Philippines. The Belian tree is the official tree of Sarawak.