Suppression

Liquidambar

Category: Medicines - plant based

Type

Voluntary

Introduction and description

 

Liquidambar, commonly called sweetgum (sweet gum in the UK), gum, redgum, satin-walnut or storax, is a genus of flowering plants in the family Altingiaceae, though formerly often treated in the Hamamelidaceae.

Both the scientific and common names refer to the sweet resinous sap (liquid amber) exuded by the trunk when cut.

The species includes:

  • Liquidambar acalycina – Chang's Sweetgum (central & southern China)
  • Liquidambar formosana – Chinese Sweetgum or Formosan Sweetgum (central & southern China, southern Korea, northern Thailand, Taiwan, Laos, northern Vietnam).
  • Liquidambar orientalis – Oriental Sweetgum or Turkish Sweetgum (southwest Turkey, Greece: Rhodes).
  • Liquidambar styraciflua – American Sweetgum (eastern North America from New York to Texas and also eastern Mexico to Honduras).

It is a very old species of tree.  This genus is known from the fossil records from the Cretaceous to the Quaternary (age range: 99.7 to 0.781 million years ago).  The genus was much more widespread in the Tertiary Than it is today. There are several fossil species of Liquidambar, showing its relict status today.

Description

 

Liquidambar are all large, deciduous trees, 25–40 metres (82–131 ft) tall, with palmately 3- to 7-lobed leaves arranged spirally on the stems and length of 12.5 to 20 centimetres (4.9 to 7.9 in), having a pleasant aroma when crushed. Their leaves can be many colors such as bright red, orange and yellow.

 Mature bark is grayish and vertically grooved.

The flowers are small, produced in a dense globular inflorescence 1–2 centimetres (0.39–0.79 in) diameter, pendulous on a 3–7 centimetres (1.2–2.8 in) stem.

The fruit is a woody multiple capsule 2–4 centimetres (0.79–1.57 in) in diameter (popularly called a "gumball"), containing numerous seeds and covered in numerous prickly, woody armatures, possibly to attach to fur of animals. The trees drop their hard, spiky seedpods in the fall by the hundreds.

The woody biomass is classified as hardwood.

In more northerly climates, sweetgum is among the last of trees to leaf out in the spring, and also among the last of trees to drop its leaves in the fall, turning multiple colors. Although a temperate species, at least one living Liquidambar tree survives in a hot and humid tropical city: Bangkok, Thailand.

Distribution

 

Species within this genus are widespread in China, Korea, Thailand, Taiwan, Laos, Vietnam, Turkey, Rhodes, North America and Mexico up to Honduras.  It has disappeared from Europe due to the once extensive glaciation in the north and the east-west oriented Alps and Pyrenees. It also disappeared from western North America due to climate change, and also from the unglaciated (but nowadays too cold) Russian Far East.

 Background

Both the essential oils of Liquidamber and those of Valerian  are being investigated for their potential use as fumigants against the Japanese termite (Reticulitermes speratus).

The fumigant toxicity of oriental sweetgum and valerian oil differed significantly according to exposure time. Oriental sweetgum showed toxicity at short exposure times (2 days), and the toxicity of valerian oil was high 7 days after treatment. ….. Hydrocinnamyl alcohol and trans-cinnamyl alcohol were found to be the major contributors to the fumigant antitermitic toxicity of oriental sweetgum oil. … Further studies are warranted to determine the potential of these essential oils and their constituents as fumigants for termite control. PMID:  25153870

 

 The wood is used for furniture, interior finish, paper pulp, veneers and baskets of all kinds. The heartwood once was used in furniture, sometimes as imitation mahogany or Circassian walnut. It is used widely today in flake and strand boards. The American sweetgum is widely planted as an ornamental, not only within its natural range.

Medicinal uses

Friar's Balsam contains Cape aloes and liquidambar resin along with Benzoin resin -  a balsamic resin obtained from the bark of several species of trees in the genus Styrax. It was invented by Dr Joshua Ward around 1760.

It was and is used as an inhalant.  It is inhaled in steam as a treatment for various conditions including bronchitis and colds. It is also used for a variety of nose problems including sinusitis, as its bacterial action helps to fight the bacterial infection.

The hardened sap, or gum resin, excreted from the wounds of the sweetgum, for example the American sweetgum (Liquidambar styraciflua), can be chewed on like chewing gum and has been long used for this purpose in Southern United States. The sap was believed to be a cure for sciatica, weakness of the nerves, etc.

In Chinese herbal medicine, lu lu tong, or "all roads open," is the hard, spiky fruit of the native sweetgum species. It first appeared in the medical literature in Omissions from the Materia Medica, by Chen Cangqi, in 720 AD. Bitter in taste, aromatic, and neutral in temperature, lu lu tong is said to ‘promote the movement of blood and qi, water metabolism and urination, expels wind, and unblocks the channels’. It is an ingredient in formulas for epigastric distention or abdominal pain, anemia, irregular or scanty menstruation, low back or knee pain and stiffness, edema with difficult urination, or nasal congestion.

 

 

References and further reading

Molecules. 2014 Aug 19;19(8):12547-58. doi: 10.3390/molecules190812547.  Fumigant toxicity of Oriental sweetgum (Liquidambar orientalis) and valerian (Valeriana wallichii) essential oils and their components, including their acetylcholinesterase inhibitory activity, against Japanese termites (Reticulitermes speratus).  Park IK1.  1Department of Forest Science, Research Institute of Agriculture and Life Science, College of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea. parkik1@snu.ac.kr.

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