Dr. Zhongzhen Zhao

Dr. Li LIANG

Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Hong Kong

Keywords: Sandalwood, Genus Santalum, Caesalpinia pulcherrima

The mystery of its origin

The aromatic material of traditional Chinese medicine can be used to smell, eat, carve, and wear. When it comes to whether a Chinese medicine is precious or not, in my opinion, there are two major factors. One is whether the resources are scarce, and the other is whether there are uses other than medicinal.

Sandalwood has both of these two qualities. It is rare, and it is multi-purpose. It is a fragrance, a medicine, as well as a carving material. It is imported. All these factors make it a precious wood.

Sandalwood is the dried heartwood from the trunks of trees in the genus Santalum of the Santalaceae family.  Santalum album L. is considered to be the best quality, and is the only species recorded in the Chinese Pharmacopoeia.

One of the earliest sources of sandalwood was Hawaii.  In the early 19th century, the Chinese used sandalwood from Hawaii to make sandalwood fans. Indeed, Hawaiian sandalwood was so highly regarded that the Chinese called the capital of Hawaii, Sandalwood Mountain. Sandalwood trees in Hawaii are now almost completely gone; they can hardly be found outside the botanical garden. 200 years ago, people lacked awareness of plant protection. When tall woods were everywhere, people did not understand the limited natural resources.

The Chinese have used sandalwood for more than a thousand years and have been relying on imported resources since then. In the 1960s, the introduction and cultivation of sandalwood in Hainan and Yunnan finally overcame the many difficulties in growing sandalwood and achieved success.

Leafy tip with flower buds of a sandalwood plant 

（Caesalpina pulcherrima (L.) Sw.）

Sandalwood tree and its host-Caesalpina pulcherrima (L.) Sw. in the Honolulu Botanical Garden

Log of sandalwood wood with decorate metal ends in a museum in Chung Tai Chan Monastery 

Botany of Sandalwood

There are 15 species and 13 varieties in the genus Santalum that are used as sources of medicinal sandalwood.  These plants are mainly distributed in India, Indonesia, Australia and some Pacific Islands. Nevertheless, resources are still in short supply.

Sandalwood is a little different from agarwood. What is the difference? Agarwood is a callus formed by fungal infection after insects attack the tree. In contrast, sandalwood is the ordinary wood of a semi-parasitic tree.  ’Parasitic’ means it attaches to a host tree with suckers that grow into and absorb nutrients from the roots of the host. While sandalwood can grow on many different host plants, it prefers plants from the legume family (Fabaceae), such as poinciana, also known as peacock flower, Caesalpina pulcherrima (L.) Sw. Sandalwood trees seen in the wild are tall trees, and sometimes the trunk has many branches. The sandalwood trees are stately, but otherwise nothing special to look at; in contrast, the poinciana flower is dazzling. Together— with the orange-red petals and the long stamens jumping out of the inflorescence of the flowers and the stateliness of the sandalwood tree—they are an elegant pair.

Poinciana (peacock flower, Caesalpina pulcherrima (L.) Sw.)

Holy Tree

Sandalwood is the sacred tree of Buddhism. Whenever I pass by the Lama Temple in Beijing, the first thing I see is Wanfu Pavilion, which is far higher than the vermilion courtyard wall and covered with bright yellow glazed tiles.

Wanfu Pavilion was built so high in order to house a sandalwood Buddha. It is a statue of Maitreya Buddha carved from giant sandalwood, 26 meters high, 18 meters above the ground, 8 meters underground, and 3 meters in diameter. In addition to the exquisite craftsmanship of the carving, the material itself is a rare treasure. The raw material was collected from a huge sandalwood tree in Nepal. In the fifteenth year of Qianlong’s reign (1750), the seventh Dalai Lama of Tibet thanked Emperor Qianlong for helping him put down the rebellion, and the Great Buddha was sent to Beijing as a gift of gratitude.

Li Shizhen wrote: “The sandalwood is a good wood.” Buddhist disciples call it the Zhan Tan. In Chinese, ‘Tan’ means ‘sandalwood’, and ‘Zhan’ means ‘bringing joy and pleasure to people’. This also explains the status of sandalwood in people’s minds and the relationship between sandalwood and Buddhism.

Sandalwood has strong corrosion resistance, and the oil yield of its xylem heartwood can reach 10%. This comes with natural preservatives, so there is no need to worry about termites or borers. Sandalwood is connected to religious beliefs and rituals. There are many Buddha statues carved out of sandalwood, and the sandalwood tree has naturally become a sacred tree.

Lama Temple in Beijing

Money Tree

2,500 years ago, Buddhism rose in India and then slowly declined, but the value of sandalwood has not declined. For thousands of years to today, the sandalwood produced in India has been a valuable marketable resource. In 2010, I visited India with Dr. Guo Ping and Dr. Menghua Wu, and experienced the status of sandalwood in the local economy and the role of sandalwood in the tourism economy. Sandalwood is regarded as a “money tree” by the locals. The roadside shops are full of Buddha statues, various gods, and small handicrafts such as elephants and peacocks, all carved out of sandalwood.

Sandalwood can be processed as a craft material in many ways. Identifying sandalwood is important in all related fields. Sandalwood with fine and firm texture, obvious oil traces and rich aroma is considered the best quality. However, everyone’s preferences are different, and whether collectors value specific handcrafted items depend on personal preference and experience. The oil extracted from sandalwood is an important raw material for the preparation of various high-end perfumes, essences, fixatives and cosmetics.

Peacock handcraft made of sandalwood

Medicinal Uses

When Sandalwood was first introduced to China, it was used primarily as incense for worshipping Buddha. Later it was gradually used in handicrafts and traditional Chinese medicine. Sandalwood is included in the Ben Cao Shi Yi of the Tang Dynasty. In the Compendium of Materia Medica, Li Shizhen recorded the efficacy of sandalwood.

Sometimes, the decoction pieces of sandalwood used in Chinese medicine are leftovers from handicraft carving. The medicinal materials are irregular, curly or broken flakes with a grayish-yellow surface and relatively rough texture. Even sandalwood sawdust can be used.

Sandalwood is one of the herbs in the formula for Suhexiang Wan. In terms of traditional Chinese medicine theory, this formula is used for treating coagulated cold syndrome.  In terms of Western diagnoses, Suhexiang Wan is mainly used for angina pectoris, myocardial infarction and chest tightness caused by coronary artery disease. Suhexiang Wan is considered to be one of the emergency medicines in traditional Chinese medicine.

Decoction pieces of sandalwood

Conservation Efforts

I have served two terms as a member of the Advisory Committee on the Conservation of Rare Animals and Plants in the Hong Kong Agriculture, Fisheries and Conservation Department. I have come into contact with many confiscated smuggled items, and fragrant wood is a major category of these smuggled goods. After much effort, some of the confiscated rare wood has been donated to the Forbidden City in Beijing and some other museums for the restoration of cultural relics and the repair of ancient buildings. It is fortunate that the confiscated smuggled wood can be put to good use. All people must comply with the laws of the country where they are located, as well as international conventions.  At the same time, nothing should be wasted, especially of such a precious resource.