Trunk and Bark
A tree that loses its leaves; is medium to high tall in height, 30–45 m, and 70(–140) cm in diameter. The bark is slightly smooth, dark grey outside, with transverse bark lines, lenticels, thin; 5 mm inner bark thickness, pink. The young branches are faceted and hairy.
Double-pinnate compound leaves, with 4–14 pairs of stipules; 10–25 cm long petiole, hairy, with glands near the petiole’s base and at the stipules’ junction. The stipules are large, oblique ovate with a half-heart-shaped base, membrane-like, with a tail at the end, and easily fall off. The veins are pinnate 4–14 cm long, with 10–45 leaflets per vein, seated, opposite. The leaflets elongate to a striped shape, with a pointed tip, oblique, blue-green underside, 6–13 × 1.5–4 mm, and the midrib is very close to the upper edge.
Compound flowers form a stemmed hump, recollected into panicles 15–30 cm long. The hump contains 10–20 flowers . The flowers are 5-petaled, with toothed calyx, lk 4 mm height, hairy; funnel-shaped crown tube, yellow-green, lk 7 mm height, hairy. It contains ten stamens or more, about 3 cm long, white and green above, fused at the base to form a tube approximately as high as the crown. The pods are 10–18 cm × 2–3.5 cm long, unopened, and irregularly broken. Flat shape seeds, ellipse, 7 × 4–5 mm in size.
Ecology and Distribution
Legumes
Sengon is found naturally in mixed deciduous forests in humid and moderate areas, with rainfall between 1,000–5,000 mm per year. We can also find this tree growing in secondary forests, along the river banks, and in the savanna, up to an altitude of 1,800 m above sea level. Sengon is well adapted to poor, high pH or salty soils and grows well on lateritic alluvial and ex-mining sandy soils.
The natural distribution of sengon includes India, Burma, Thailand, Cambodia, Laos, China, Vietnam, and Indonesia, introduced to Australia. In Indonesia, sengon spreads in Java, Bali, and Nusa Tenggara brought in and cultivated in Sumatra and Kalimantan.
Benefit
Wood
Sengon produces light to moderately light wood, with a density of 320–640 kg/m³ at a moisture content of 15%[8]. Slightly dense, straight-grained and a bit rough, but easy to work with. The heartwood is a glossy yellow to ivory-brown; its strength and durability are classified into solidity class III-IV and durability class III-IV. Subterranean termites do not attack this wood due to the presence of extractive substances in the wood. However, burial experiments in the Philippines found that sengon wood (A. Chinensis) lasts only 16 months, while langir wood (A. Saponaria) lasts up to 3 years and weru wood (A. Procera) lasts up to 10 years.
Sengon wood is commonly used to make crates, boats, houses and bridges compound [4]. In Sabah, A. Chinensis wood is traded as ‘batai’ wood, in combination with A. Pedicellata and Paraserianthes falcataria.
Agroforestry
In coffee and tea plantations, A. Chinensis is often grown as shade, especially in mixtures with jeunjing (P. Falcataria) and dadap (Erythrina spp.). Sengon is favoured as an ornamental plant and shade in gardens, farms, and roadsides. This tree is also planted to protect sloping land and also improve the soil.Sengon roots are nitrogen fixing.
Other uses
Essentialy like the bark of ki hiang, sengon bark contains ingredients we can use to anesthetize fish in rivers. In the past, this bark was also used as an ingredient of soap.
Although goats can eat the leaves, the bark of the branches is poisonous because it contains saponins.
Similar type
The stature and wood of Paraserianthes Falcataria are more or less similar to that of the sengon tree and wood, so their names are often interchanged. By the Javanese, P. Falcataria—originally from Maluku—is called sengon laut, sengon sabrang, or sengon landi.
