Camphora officinarum is aspecies ofevergreen tree indigenous to warm temperate to subtropical regions of East Asia, including countries such as China, Taiwan, Vietnam, Korea, and Japan. It is known by various names, most notably thecamphor tree,camphorwood orcamphor laurel.^[1][2][3]

Camphora officinarum
An ancient camphor tree (estimated to be over 1,000 years old) in Japan
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Magnoliids
Order:	Laurales
Family:	Lauraceae
Genus:	Camphora
Species:	C. officinarum
Binomial name
Camphora officinarum Nees
Synonyms
Laurus camphora L. Persea camphora (L.) Spreng. Cinnamomum camphora (L.)J.Presl. Camphora officinalis Steud. Camphora camphora (L.) H. karst.

Camphora officinarum grows up to 20–30 m (66–98 ft) tall.^[4] In Japan, where the tree is calledkusunoki, five camphor trees are known with a trunk circumference above 20 m (66 ft), with the largest individual,Kamō no Ōkusu (蒲生の大楠, "Great camphor ofKamō"), reaching 24.22 m (79+1⁄2 ft).^[5]

The leaves have a glossy, waxy appearance and smell ofcamphor when crushed. In spring, it produces bright green foliage with masses of very small white fragrantflowers from which its common namesake "smells good tree" in Chinese香樟xiang zhang was given. It produces clusters of black, berry-likefruit around1 cm (3⁄8 in) in diameter. Its palebark is very rough and fissured vertically.

The species is native to China south of theYangtze River, Taiwan, southern Japan, Korea, India, and Vietnam, and has been introduced to many other countries.^[4]

In Australia, the larval stages of two native butterflies, thepurple brown-eye andcommon red-eye feed on camphor despite it being an introduced plant.^[6]

Camphor laurel was introduced to Australia in 1822 as anornamental tree for use in gardens and public parks. It has become anoxious weed throughoutQueensland and central to northernNew South Wales, where it is suited to the wet, subtropical climate. The camphor content of theleaf litter helps prevent other plants from germinating successfully, helping to ensure the camphor's success against any potentially competing vegetation,^[7] and the seeds are attractive to birds and pass intact through the digestive system, ensuring rapid distribution. Camphor laurel invades rainforests and pastures, and also competes againsteucalyptus trees, certain species of which are the sole food source ofkoalas. In its favour, however, younger camphor laurel trees can quickly develop hollows, which can be utilised by wildlife, whereas natives can take hundreds of years to develop hollows.^[8]

Introduced to thecontiguous United States around 1875, the species has becomenaturalized in portions ofAlabama,California,Florida,Virginia,Georgia,Hawaii,Louisiana,Mississippi,North Carolina,Texas, andSouth Carolina.^[9] It has been declared a category Iinvasive species in Florida.^[10]

The species is cultivated for camphor and timber production. The production and shipment of camphor, in a solid, waxy form, was a major industry in Taiwan prior to and during the Japanese colonial era (1895–1945). It was used medicinally and was also an important ingredient in the production ofsmokeless gunpowder andcelluloid. Primitive stills were set up in the mountainous areas in which the tree is usually found. The wood was chipped; these chips were steamed in a retort, allowing the camphor to crystallize on the inside of a crystallization box after the vapour had passed through a cooling chamber. It was then scraped off and packed out to government-run factories for processing and sale. Camphor was one of the most lucrative of several important government monopolies under the Japanese.

The wood has aninsect-repellent quality.^[11]

Camphor is a white crystalline substance, obtained from the treeC. camphora. Camphor has been used for many centuries as a culinary spice, a component of incense, and as a medicine. It is also an insect repellent and a flea-killing substance.

The species containsvolatilechemical compounds in all plant parts, and the wood and leaves aresteam distilled for theessential oils. Camphor laurel has six different chemical variants calledchemotypes, which arecamphor,linalool, 1,8-cineole,nerolidol,safrole, andborneol. In China, field workers avoid mixing chemotypes when harvesting by their odour.^[12][13]

Camphor type

This type is dominant in India and Sri Lanka.^[14] The wood oil is separated into four fractions after camphor is removed by filtration, termed white, yellow, brown, and blue camphor oil.^[15] Oil contains 54–97% camphor.^[16]

Linalool type

This type is commonly found in Taiwan and Japan. Oil contains 80–85 linalool^[14] (another source gives a wider range of 58–92%).^[16] The leaf oil is called "ho leaf oil", the wood oil "ho wood oil" (after removal of safrole), and the mixture of both "shiu oil".^[15]

Cineole (eucalyptol) type

This type is dominant in Madagascar. The oil contains 40–50% cineole^[14] (another source gives 32–52%).^[16] The essential oil from the Madagascar tree leaves is commercially known asravintsara.^[14][15]

The cineole fraction of camphor laurel is used in China to manufacture fake "eucalyptus oil".^[17]

Nerolidol type

Oil contains 16–57% nerolidol.^[16]

Safrole type

This type is mentioned by few recent sources.

Borneol type

This type is commercially useful in China, as borneol is used in medicine. Oil contains 67–82% (-)-borneol.^[16] Increased monoterpene production can be induced by mechanical damage.^[18]

Isoborneol type

At least two sources mention this type.^[19][20]

Certain trees in Japan are considered sacred. An example of the importance of asacred tree is the enshrined 700-year old camphor growing in the middle ofKayashima Station. Locals protested against moving the tree when the railway station had to be expanded, so the station was built around it.^[21]

• Sandalwood – Class of woods from trees in the genus Santalum
• My Neighbor Totoro – 1988 film by Hayao Miyazaki

• Camphor laurel fact sheet—Produced by the Queensland Department of Primary Industries and Fisheries
• Campaign to stop the spread of camphor laurels in Australia
• Yang, Zerui; Zhan, Ting; Xie, Chunzhu; Huang, Song; Zheng, Xiasheng (March 2023). "Genome-wide analyzation and functional characterization on the TPS family provide insight into the biosynthesis of mono-terpenes in the camphor tree".Plant Physiology and Biochemistry.196:55–64.Bibcode:2023PlPB..196...55Y.doi:10.1016/j.plaphy.2023.01.039.PMID 36696798.