Properties and characteristics of Tualang (Koompassia excelsa) in Sarawak / Dora Paul Sajep

Tualang tree (Koompassia excelsa) from Fabaceae (Leguminosae) family is the biggest where its occurs, Tualang tree is easy to recognized with the existence of bees nest under the branches, colour of bark that grey and smooth, wide-spreading buttresses and small leaflets. Sapwood is grey white in colour and distinct from the dark red-brown heartwood. The texture of the wood is coarse but even, with deeply interlocked grains. Parenchyma is wing-like aliform confluent around the vessel. Tualang is totally a protected species in Sarawak. This timber is categorized in Strength Group A that is under very heavy timber with air-dry density averaging 880 kg/m3 (55 lb/ft3). The timber is generally easy to work in the green condition but slight difficulties may be encountered in the resawing and boring of air-dry material. The timber dries moderately slowly with slight end checks and surface-checks as the main source of degrade. Severe splitting may occur in boards containing included phloem. The timber is suitable for all form of heavy construction when treated with preservatives. Tualang's barks also useful to prepare a medicinal bath against fever, meanwhile bees nest under its branches that produce honey are an economic sources for villagers.