Incense Tree

Scientific Name : Aquilaria sinensis (Lour.) Spreng.
Common Name : Incense Tree
Chinese Name : 土沉香, 牙香樹, 白木香
Family : THYMELAEACEAE
Local distribution status : Native species

Anecdotes on plants

Origins Guangdong, Guangxi, Hainan and Fujian.
Applications As we all know, Incense Tree is the source of agarwood, which is a valuable incense. When the trunk of old tree injured, fungi would invade. At that time the tree releases resin for defence, this process is called “agar formation”. Hence agarwood is the product of Incense Tree and fungi. Apart from being an incense, applied as a Traditional Chinese Medicine, agarwood (Chenxiang) exhibits the functions of moving qi and relieving pain, warming the centre and stopping vomiting, promoting qi absorption and calming panting. The bark is the raw materials of high-quality papers, while the timber can be used to produce refined fragrance oil and joss sticks.
Relationship with Hong Kong According to a historian Professor LO Hsiang-Lin, the Chinese character “Hong (香, means fragrant)” in Hong Kong (香港) is referring to the Incense Tree, ascribed by Hong Kong was the main place of production and port (“港” in Chinese, transliteration as “Kong”) of conveyance.
Ecology The species is one of the Fungshui wood species and also native to Hong Kong, providing shelters and nectars to the local animals. However, its value threatens its survival, as it is targeted by illegal collectors in recent years. Incense tree is graded as “Vulnerable” species in the International Union for Conservation of Nature Red List of Threatened Species, and also recorded in the China Plant Red Data Book as “Vulnerable” species. Meanwhile, Incense tree is shortlisted in the local Rare and Precious Plants of Hong Kong, under the control of Hong Kong Ordinance Chapter 586 The Protection of Endangered Species of Animals and Plants Ordinance. The aforementioned reflects the situation of the wild species is extremely precarious. Hence we ought to protect and treasure the Incense Tree in urban areas and countryside.

Traits for identification

Growing habit Evergreen tree.
Height To 15 m.
Stems Bark grey, smooth. Branchlets terrete, rugose, like the wrist of human.
Leaves Subovate, obovate to elliptic, apiculate. Leathery in texture. Glossy, dark green to purplish green adaxially, light green abaxially. Lateral veins many, slender.
Flowers Yellowish green, fragrant at night. Calyx shallowly campanulate, 5-lobed, with 10 scale-like petals attached to the throat. Petals hairy.
Fruits Capsule ovoid, apex apiculate, base tapering, pear-shaped, green. Densely pubescent in yellowish brown on surface, 2-valvular dehiscent when mature, 2 seeds inside hanging down with the attachment of filiform structure, like pendants.
Seeds Dark brown, ovoid, with tail-shaped appendage at the tips.
Flowering period March to May in Hong Kong.
Fruiting period September to October in Hong Kong.
Remarks

Scientific name above is based on Hong Kong Herbarium website : https://www.herbarium.gov.hk/en/hk-plant-database/plant-detail/index.html?pType=species&oID=6214

Scientific names from other databases
Flora of China : Aquilaria sinensis (Loureiro) Sprengel
Plants of the World Online : Aquilaria sinensis (Lour.) Spreng.

Reference