It is hard to believe nowadays but polluted Hong Kong was once known as the ‘Heung’ or Fragrant Harbour, thanks to its trade in legendary agarwood. Today this heartwood from Aquilaria species commands the highest price of any natural substance, a staggering US$10,000 for but a single kilogram.
Away from the worse of the pollution in Hong Kong’s lush green northern suburbs near the border with mainland China, farmer Koun-wing Chan is working to keep that legend alive. Returning from Ireland, he is reviving traditional cultural techniques for the Incense Tree,
Aquilaria sinensis, producer of agarwood, used to make incense and joss sticks; the resin is used in traditional Chinese medicine. He may not have long to wait, since even the young trees can be persuaded to produce agarwood by inoculation and infection.
The tree is endemic to south China but threatened by habitat loss, as are the dozen or so other
Aquilaria species in Southeast Asia that produce the valuable wood. In fact, China’s Incense Tree is replacing the Malayan Eaglewood Tree,
A. malaccensis, once the preferred source until virtually eradicated in the wild and only now being re-established on plantations.
Not any
Aquilaria, wild or cultivated, will produce agarwood, however. First they must become infected with a parasitic ascomycetous mould,
Phaeoacremonium parasitica. In response to the attack, the pale coloured heartwood darkens into a dense, resinous core. Appreciated for its distinctive fragrance, which has never been artificially reproduced successfully, it has long been valued throughout southern and eastern Asia cultures. More recently Western perfumers have joined in, raising the world market to an estimated US$6-billion to US$8-billion annually.
It may be known as gaharu, jinko, aloeswood, agarwood or oud amongst dozens of others. But whatever the name, it is unlikely that simple visual inspection can detect if a tree has become infected within by the desired mould. Hence, wild trees were indiscriminately felled and the trunks split open in the hopes of discovering the treasure hidden in its core. Such has led to massive losses wherever the tree occurs in its natural habitat.
The resinous gaharu wood was formerly imported into China for medicinal purposes, according to Wee Yeow Chin & Husuan Keng authorative
An Illustrated Dictionary of Chinese Medicinal Herbs (1992). The grated wood is included in preparations used to treat rheumatism, smallpox and illness during and after childbirth. It is considered a stimulant, aphrodisiac, tonic, diuretic, and expels gas from the system. The oil is also believed to be an aphrodisiac, both as oil and as incense. All for $10,000 or so.
