Botanical Description
Liquidambar is a genus of trees, commonly called sweetgum, which derives its name from the brown sap produced by these trees which, if left to harden, can be made into chewing gum. This deciduous tree is recognized by the quarter sized, spiny, woody seedpods it produces. There are four species of sweetgum including Liquidambar orientalis L. (L. orientalis), Liquidambar formosana Hance (L. formosana), Liquidambar styraciflua L. (L. styraciflua), and Liquidambar acalycina (L. acalycina) worldwide.
Liquidambar formosana, commonly known as the Chinese sweet gum or Formosan gum, is a species of tree in the family Altingiaceae native to Vietnam.
Liquidambarformosana is a large, native, deciduous tree that grows up to 30-40m tall. The leaves are 10~15 cm wide. and are three-lobed unlike five- to seven-lobed leaves of most American Liquidambar species. The foliage of the L. formosana turns a very attractive red color in autumn. Leaves grow in an alternate arrangement, and are simple, palmately-veined, with serrated margins. Roots can be aggressive, and branches are usually covered with corky projections. The individual flowers of L. formosana are monoecious. However, both sexes can be found in the same plant. Male flowers are in catkins, female flowers form dense spherical heads, and the fruit is burr-like because of the persistent styles
Liquidambarformosana grow mostly in woodland in warm temperate zones. It requires moist soil and can grow in light to no shade area. It is usually found in Vietnam and Southern China.
Sweetgum resin comes from the sap of injured Liquidambar trees. Liquidambar essential oil is steam distilled and extracted from the resin. The resin is light yellow, slightly balsamic, bitter and exudes a spicy cinnamon aroma.
The resulting substance is a unique combination of volatile aromatic compounds that are not commonly found in other essential oils. It emits a unique aroma with pine, floral, and spicy notes. While it is primarily known for its benefits when applied topically, it is also commonly used aromatically to promote a calm and restful environment.
Liquidambar essential oil also has a high boiling point and can act as an effective odor fixative when used in fragrance. Therefore, it is a unique fragrance agent, which can be seen in some enhanced high-end perfume formulations.
How to tapping resin
The oleoresin tapping practice that was utilized in this work not only increases resin tapping efficiency but also ensures the sustainability of the trees and the ecosystem. Mature L. formosana trees with DBH (diameter at breast height) ≥ 60 cm, without pest infection, qualified for oleoresin tapping. The oleoresin tapping was carried out by local farmers at average temperatures above 15℃. The tapping surface was on the sun-facing side of the trunk.
An area of the trunk was shaved of bark, a medial groove was cut in the center of the shaved area, and a V-shaped ditch was cut from top to bottom along the vertical direction of the trunk. The V-shaped angle (β) was between 60° and 80° (Figure) and was cut to the first or second annual ring of the tree. A minimum 10-cm space was preserved between each V-shaped ditch to ensure the health of the trees. The oleoresin aggregations were located at the bottom of the V-shaped ditch, which guided the oleoresin into a container. Immediately after the resin was collected, it was transferred to amber-colored glass bottles and stored at 4℃ until distillation.
Liquidambar Formosa Resin Specification
The major components:
(E)-caryophyllene (3.3%-64.4%)
α-pinene (0.6%-34.5%)
β-pinene (0.6%-26.0%)
Camphene (0.3%-17.3%)
Limonene (0.2%-7.9%)
Uses
An aromatic resin is obtained from the trunk of this tree. It forms in cavities of the bark and is harvested in autumn. It is used as a raw material for the perfume and pharmaceutical industry and in the manufacture of varnish and incense. It is used medicinally.
The resin from the stems is used to treat bleeding boils, carbuncles, toothache, and tuberculosis.
It is mixed with Rhamnuscrenata fruits and used as a suppository for constipation.