Botanical Name: Dyera costulata
Species: D. costulata
*Alstonia costulata Miq.
*Alstonia eximia Miq.
*Alstonia grandifolia Miq.
*Dyera laxiflora Hook.f.
Common Names:Hill Jelutong, Jelutong, Jelutung, Button to view the previous items of the carousel.
Habitat: Dyera costulata is native to Southeast Asia – Malaysia, Thailand, Indonesia.It grows in Malaysia, Borneo, Sumatra and southern Thailand. Its natural distribution is scattered locales in low-elevation tropical evergreen forest. It grows on the lowland or hilly forest up to 300 metres. In undisturbed forests at elevations up to 400 metres. Usually on hillsides and ridges on clayey to sandy soils. In secondary forests usually present as a pre-disturbance remnant.
Dyera costulata is a large, deciduous tree with a spreading crown that grows up to 75 m in height with diameters to 3 m (10 ft), The trunk is not buttressed and can be up to 3 m in diameter and up to 30 m unbranched. And boles clear and straight for 30 m (90 ft). Smooth dark grey bark with quadrangular scales and branches arranged in verticils; all parts of the plant contain a white latex that exudes abundantly from the wounds.Simple leaves, arranged in verticils of 6-8, oblong-elliptic with entire margin, obtuse or slightly pointed apex and prominent veins, coriaceous, 5-30 cm long and 3-12 cm broad, glossy green above, greyish below; the new leaves are of bronze colour.
Axillar and terminal cymose inflorescences, on a 3-8 cm long peduncle, bearing numerous tiny flowers, that last one night only, with hemispherical calyx with 5 rounded lobes, white or yellowish green imbutiform corolla with 1-3 mm long tube and lobes 3-8 mm long and 1-2 mm broad.
The fruits are woody follicles in pair, 20-40 cm long and of 2,5-3,8 cm of diameter, dehiscent, covered by tiny scales of rust colour, containing numerous winged flat seeds, 5 cm long and 2 cm broad, wing included, dispersed by the wind.
It propagates by seed, that has a germinability lasting less than one year, previously kept in water for one day, in sandy loam maintained humid at the temperature of 24-28 °C; it reproduces also by cutting.
A plant of the wet, lowland tropics, where it is usually found at elevations up to 400 metres, exceptionally to 800 metres. Requires a sunny position – the tree develops a wide crown when growing in the sun in order to ‘claim’ its territory. Prefers a well-drained soil, often growing on hills and ridges in the wild.
Seed – the small seed has a limited viability of less than a year. Pre-treatment is not necessary, but soaking the seed in water for 12 hours prior to sowing can speed up the germination process[ 325 ]. Germination rates are usually good, with 80 – 90% of the seeds sprouting. Seedlings can be potted up when the first pair of leaves has emerged and planted out when 30cm tall.
The resinous fruits are used for medicinal purposes.
The latex, obtained by tapping the trunk, is used for the production of chewing gum, celluloid, linoleum and the insulation of electric cables. Beside this it serves as admixture for cement, paints and paper. The latex has a number of speciality uses such as pattern making in foundry work, for drawing boards, pencils, picture frames, dowels, carving, blackboards, wooden toys, clogs, brush handles and battery separators, and it is also used for furniture parts, door knobs, ceilings, partitioning, matchsticks, matchboxes and packing cases. The resinous fruits serve as torches. They are also burnt to repel mosquitoes. The roots are used as a substitute for cork. The heartwood is creamy white to pale straw coloured with the frequent presence of large latex canals; it is not differentiated from the sapwood. The grain is mostly straight; texture moderately fine and even; slightly lustrous; without taste but with a slight sour odour that is distinctive. The wood is very light in weight; soft; it is not durable, being susceptible to fungi, dry wood borers and termites. It seasons rapidly with only a slight risk of checking or distortion; once dry it is stable in service. The wood works easily with hand and machine tools, but they need to be kept very sharp in order to obtain a smooth finish; latex in the wood may clog the sawteeth; nailing and screwing are poor; gluing is correct. The wood is excellent for carving and is also used, among other things, for making patterns, pencils, matches, match-boxes, boxes and crates, furniture components, interior joinery and panelling, drawing boards, blockboard and veneer.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.