Bornean Ironwood (Eusideroxylon zwageri)

Product description

This large hardwood tree is known as Bornean ironwood, and that name comes from the highly durable and hard wood harvested from these trees. It is considered one of the best hardwoods in Southeast Asia, which is why it is used locally as a construction material for traditional Bornean houses and furniture. Ironwood is a name given to specific wood species when its density exceeds that of water: more than 1,000 kg per cubic metre. At that density, machines and tools to cut the wood quickly become blunt. Because of the high value of the wood, overexploitation is unfortunately a problem for the survival of this species. It does not help that it is also a very slow grower with a growth rate of only 50 cm per year. They can eventually reach heights of up to 50 metres in the rainforest, but these are old trees that are often 1,000 years old. So if a tree is cut down, it can take a very long time for a new specimen to grow up again. The species is listed on the IUCN Red List as vulnerable. It is the only species of the genus Eusideroxylon.

Like many other forest giants, this species has a broad root system with plank roots for sufficient stability. Young leaves are reddish and thus appear poisonous to many herbivores. Later, they turn to bright green and grow to about 14-18 cm in size. The flowers of this tree are pale yellow and form large fruits after pollination. These fruits have limited medicinal uses and are generally considered poisonous. The species can be kept as a houseplant, where the plant can be kept small by pruning. Provide a semi-sunny location, permeable soil and water the plant regularly.

Sowing description: The huge seeds (+/- 10cm) can be sown in sowing soil. Keep the soil constantly slightly moist at a temperature of 25-30grC. Germination usually after a few weeks.