Agar Wood, Pak Muk Heung, White Wood Incense
Aquilaria sinensis

Family: Thymelaeaceae

What it is like

One of the three species of the Aquilaria genus that are great sources of a resin used as perfume and incense is Agar Wood or Aquilaria sinensis. It is a tropical, evergreen tree that grows up to 15 m tall and is found in East Asia. It is also widely cultivated for its wood and fibre. Due to such highly valuable uses, the tree has been over exploited in the wild. Alike to Aquilaria crassna and Aquilaria malaccensis, Aquilaria sinensis is used medicinally to lower fever and as relief from spasms. The incense is as well used against cancer, abdominal pains, asthma, colic, and diarrhoea. The wood, on the other hand, can be grated and prepared in various ways for treating small pox, rheumatism, and abdominal pains. Wood decoction has anti-microbial properties.

Aquilaria sinensis is an evergreen Tree growing to 15 m (49ft) by 12 m (39ft) at a slow rate. See above for USDA hardiness. It is hardy to UK zone 10. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in heavy clay and nutritionally poor soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers moist soil.

Height (m): 15

Where it is found

Lowland forests, sunny places on slopes or along roadsides.

E. Asia - tropical southern China.

Conservation Status: Vulnerable

Countries/locations it is found in

Coming Soon

How it is used

Food

Rating: 0

Medicine

Rating: 3

Agar is an astringent, stimulant, tonic herb that relieves spasms, especially of the digestive and respiratory systems, and lowers fevers. In Western, Chinese and Indian medicines the incense is used against cancer, especially of the thyroid gland. In China it is applied as a sedative against abdominal complaints, asthma, colic and diarrhoea, and as an aphrodisiac and carminative. The grated wood enters into various preparations used especially during and after childbirth, and to treat rheumatism, smallpox and abdominal pains. Decoctions of the wood are said to have anti-microbial properties, e.g. against Mycobacterium tuberculosis and Shigella flexneri.

Antiasthmatic: Treats asthma.

Antidiarrhoeal: Provides symptomatic relief for diarrhoea. Also see Astringent.

Antirheumatic: Treats rheumatism.

Aphrodisiac: Increases the sexual appetite.

Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.

Cancer: Used in the treatment of cancer.

Carminative: Reduces flatulence and expels gas from the intestines.

Febrifuge: Reduces fevers.

Stimulant: Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.

Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.

Other

Rating: 4

Other uses rating: Medium (3/5). Other Uses Agar wood is the rare and famous, resin-containing heartwood that is produced mainly from old and diseased trees of several members of this genus. In trade a distinction between the wood from these species is rarely made. The fragrance produced by the burning agar wood has been highly valued for thousands of years, and its use as incense for ceremonial purposes in Buddhism, Confucianism and Hinduism is widespread throughout eastern and southern Asia. In Thailand it is put into funeral pyres, while in Japan, the incense is used in tea ceremonies. Wood only partly saturated with resin but still fragrant, and occasionally also the wood remaining after distillation, is made into sticks called 'joss-sticks' or 'agarbattis' which are burnt as incense. The incense is also used as an insect repellent. Agar-wood oil is an essential oil obtained by water and steam distillation of agar wood. It is used in luxury perfumery for application in e.g. oriental and woody-aldehydic bases, 'chypres' and 'fougeres'. It produces interesting odour notes with clove oil, e.g. in carnation bases. The oil is so rare and expensive that it is only produced on request. Agar-wood oil is a yellow to dark amber, viscous liquid with a characteristic balsamic and woody odour. Its aroma has some resemblance with vetiverol or styrax and has a sweetness similar to that of sandalwood oil. Its odour is long-lasting and exhibits a good tenacity in applications. The silvery inner bark can be removed from the trunk in a single large sheet. It is highly valued for its strength and durability and is made into cloth and ropes. It is also made into writing material which was formerly only used for chronicles of important events and religious books. The timber of undiseased trees, known as 'karas', is soft and very light with a density of about 400 kg/m3 air dry. It is creamy white to pale yellowish-brown or greyish-brown, heartwood and sapwood not clearly differentiated. The texture is rather coarse and the wood diffuse-porous. It is suitable for making boxes, light indoor construction and veneer. The scented wood differs from the normal wood due mainly to deposition of an aromatic resin. The resin is concentrated in the included phloem strands. Because of the resin content the scented wood is relatively hard, brittle and heavy.

Containers: Plants, such as gourds, that can be used as containers. Does not include baskets or containers made from wood.

Cosmetic: Used to improve the physical appearence of a person.

Fibre: Used for making cloth, rope, paper etc.

Incense: Aromatic plants that can be burnt to impart a pleasant smell, repel insects and disinfect closed areas.

Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.

Resin: Used in perfumery, medicines, paints, soap making etc. This also includes turpentine, which is extracted from many resins and used as a preservative, water proofer etc,

String: Plants that can be used for string or can be easily made into a string. See also Fibre. Plants for ropes may be included.

Weaving: Items such as grass and palm leaves that are woven together for making mats, baskets etc. See also Basket making and Fibre.

Wood: A list of the trees and shrubs that are noted for having useful wood.

Scented Plants: Plants noted for their scent

How it is grown

Grows best in undulating terrain in the moister lowland tropics, being found at elevations of 200 - 700 metres. It prefers an annual rainfall of 1,500 - 6,500 mm, a mean annual maximum temperature of 22 - 28c and a mean annual minimum temperature of 14 - 21c. Prefers heavy soils developed from gneiss and other metamorphic rocks, but it also grows well on sandy loams developed from sandstone. The extremely high prices paid for high quality agar wood and for the essential oil and the indiscriminate felling of both diseased and healthy trees threaten natural stands of Aquilaria including Aquilaria sinensis to extinction. Research into possibilities of artificial induction and stimulation of agar wood formation is therefore urgently required and may offer high economic returns, especially as trials indicate that management of plantations presents no great difficulties. Unless such methods are developed, Aquilaria malaccensis may soon be extinct. Plantations have been established, mainly for experimental purposes, to test methods for the induction of agar wood formation. Three closely related species of Aquilaria are considered to be the major sources of agar wood and are distinguished by the length of their calyx lobes: Aquilaria crassna, which comes from Indo-China, has lobes 12 - 15mm long. Aquilaria malaccensis, from India, and Malaysia has lobes 2 - 3mm long. Aquilaria sinensis, from China, has lobes 8mm long. A number of other species are less important sources of agar wood, including some minor Aquilaria spp., Enkleia malaccensis and the timbers Gonystylus bancanus and G. macrophyllus. Agar wood formation is a pathological process taking place in the stem or main branches where an injury has occurred. Fungi are involved in the process, but the process itself is not yet fully understood. Damage by boring insects is often associated with the infection. It is believed that the tree is first attacked by a pathogenic fungus, which causes it to weaken. Infection by a second fungus causes the formation of agar wood, but it is unclear whether it is a product of the fungus or the tree. The fungus implicated in the formation of agar wood in A. malaccensis is Cytosphaera mangiferae, while Melanotus flavolives is assumed to play a similar role in this species.

Propagating it: Seed should be sown immediately, as it remains viable for only about 1 month. It is sown in nursery beds, about 5 mm deep in a mixture of soil, sand and manure and kept under light shade. Germination starts after 10 - 12 days and is normally complete after 1 month. Seed sown immediately after collection has about 65% germination, falling to 45% after 1 week and only 5% after 3 weeks in storage. The seedlings are very prone to insect attack. Seedlings are pricked out into containers 40 - 45 days after germination when they are 3 - 5 cm tall, and are kept under shade. They are ready for transplanting when 30 - 35 cm tall and 10 - 12 months old. Transplanting bare-rooted seedlings has been tried successfully in some areas. Fruit harvested for seed should be collected when mature but still green. A medium- sized tree produces about 2,000 seeds per year, but seed production may fluctuate greatly between years. The fruits are dried in the shade for about 2 days, they then burst and release the seed.

Best place to grow:

Habit: Tree

Hardiness: 10-12

Growth: Slow

Soil: Light (sandy), medium, heavy (clay)

Shade: No shade

Moisture: Moist

Things to keep in mind

Its other names

Local names

Agar Wood, Pak Muk Heung, White Wood Incense

Synonyms

Agallochum sinense (Lour.) Kuntze Aquilaria grandiflora Benth. Aquilaria ophispermum Poir. Ophisperm