Sentang
| Sentang | ||||||||||||
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| Scientific name | ||||||||||||
| Azadirachta excelsa | ||||||||||||
| ( Jack ) Jacobs |
Sentang ( Azadirachta excelsa ) is a species of tree from the genus Azadirachta within the mahogany family (Meliaceae).
description
Azadirachta excelsa . grows as a tree that reaches heights of up to 50 meters and trunk diameters of up to 120 centimeters. The trunk is straight, rarely with weak buttress roots. The bark is initially smooth, it is pink-gray to pink-brown in color, on old trees it becomes longitudinally cracked to scaly, with the bark scales curling up on both sides. The heartwood is reddish, the sapwood is white. The crown is rounded, irregular and not very dense, the main branches ascending. Young twigs are downy hairy, but soon balding. The tree is deciduous, the leaves are shed for about three months of the year.
The leaves reach about 20 to 60, exceptionally up to 90 centimeters in length. They are heaped in tufts at the ends of the branches. The leaves are unpaired (rarely paired) pinnate, with a 5 to 8 centimeter long petiole that is swollen at the base. They are composed of 7 to 11 pairs of leaves. The egg-shaped, sometimes uneven, leaflets are about 2 millimeters long with stalk, their apex is usually pointed to pointed, they reach a maximum (in the middle of the leaf) about 12.5 centimeters long and 3.5 centimeters wide. The leaf margin is whole (different from neem tree). The leaves are pink when they shoot, and before the leaves fall they turn yellow.
The small, greenish-white flowers are in 20 to 45, up to 70 centimeters long, upright, three- or four-fold branched paniculate inflorescences. The individual flowers are stalked 1 to 3 millimeters long. The approximately one millimeter wide calyx is downy and hairy and pale green, the calyx tips are round to slightly pointed. The five petals are oblong-spatulate with a rounded tip, at the base they are narrowed like a stem and reach 5 to 6.5 millimeters in length and 1.5 to 2.2 millimeters in width. They are hairy on the outside. The white to greenish stamen tube reaches about 2 millimeters in diameter, it has ten ribs and is serrated and wavy on the edge, the 8 to 10 anthers are inside and above. The fruit is a mostly solitary, elliptical stone fruit from 2.4 to 3.2 centimeters in length, it is ripe yellow in color. Their shell is leathery, the pulp, which contains some milk juice, is edible. The seeds smell of garlic when damaged.
ecology
The species grows in the tropical rainforest and monsoon forest . It occurs in the primary forest, but more often in older secondary forests, at an altitude of up to 350 meters. It prefers well nutrient-supplied, not waterlogged clay soils to sandy loam soils, with pH values of 5.0 to 6.5. It achieves good growth performance with annual precipitation of over 2000 millimeters and an annual temperature of 22 to 27 ° C. The length of the annual dry season must not exceed three months. It is sensitive to cold and not frost-tolerant.
The fruits are ripe about 12 weeks after fertilization . The fruits are eaten by birds and bats.
distribution
The natural range of Azadirachta excelsa includes Vietnam , Indonesia , Malaysia , Brunei , the Philippines, and western New Guinea .
Economical meaning
Sentang is a valuable forest tree whose red-brown to brown heartwood is particularly popular for the production of veneer . The species is used in primary stands, but is also widely planted as a forest tree. The cultivation is mainly limited to the natural distribution area, but smaller cultivation areas exist almost worldwide in suitable climates. The species is mainly traded locally, including as construction timber; there are small exports to Japan. It is mainly used for interior construction, as the wood is easy to work with, but not very weather-resistant.
The wood reaches a density of 550 to 780 kilograms per cubic meter (with 15 percent moisture). Annual rings are not visible. It is moderately durable, and the sapwood is susceptible to termites, beetles and wood-destroying fungi.
The seeds of Sentang, like those of the closely related neem tree, contain azadirachtin . However, only a small amount of extract is obtained from this species. The young shoots are used as vegetables.
The IUCN estimates the species as harmless (least concern).
Taxonomy and systematics
The species was first described as Melia excelsa from the island of Penang (Malaysia) by the Scottish botanist William Jack. A synonym is Azadirachta integrifolia Merrill. Besides the neem tree Azadirachta indica , it is the only species of the genus Azadirachta , described by De Jussieu in 1830. The genus is closely related to the genus Melia , from which it can be derived. a. differs from the simply pinnate leaves.
Individual evidence
- ^ Azadirachta excelsa at Tropicos.org. Missouri Botanical Garden, St. Louis, Retrieved November 19, 2018.
- ↑ Azadirachta excelsa in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved November 19, 2018.
- ↑ David J. Mabberley (Ed.): Meliaceae. In: E. Soepadmo, LG Saw, RCK Chung, R. Kiew (eds.): Tree Flora of Sabah and Sarawak. Vol. 6. Sabah Forestry Department, Forest Research Institute Malaysia, Sarawak Forestry Department, 2007. Pages 113-115
- ↑ a b Dorthe Jøker (2000). Azadirachta excelsa. Seed Leaflet no.13. Københavns Universitet, 2000.
- ↑ a b Orwa et al., 2009: Profile at Agroforestry Database 4.0.
- ↑ RHMJ Lemmens, I. Soerianegara and WC Wong (eds.): Plant Resources of South-East Asia No. 5 (2). Timber trees: Minor commercial timbers. Backhuys Publishers, Leiden 1995. ISBN 90-73348-44-7 .
- ↑ Azadirachta excelsa in the IUCN Red List of Threatened Species 2018.1. Retrieved November 19, 2018.
- ↑ M. Jacobs (1961): The Generic Identity of Melia excelsa Jack. Gardens' Bulletin (Singapore) 18 (4): 71-75.