''Cymbopogon citratus'', commonly known as West Indian lemon grass or simply lemon grass, is a tropical

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...

native to

Maritime Southeast Asia Maritime Southeast Asia comprises the countries of Brunei, Indonesia, Malaysia, the Philippines, Singapore, and East Timor. Maritime Southeast Asia is sometimes also referred to as Island Southeast Asia, Insular Southeast Asia or Oceanic Sout ...

and introduced to many tropical regions. ''Cymbopogon citratus'' is often sold in stem form. While it can be grown in warmer temperate regions, such as the UK, it is not hardy to frost.

Morphology

''Cymbopogon citratus'' is part of the grass family, Poaceae. They contain simple, bluish-green leaves with entire margins and are linear in shape. The blades tend to be 18–36 inches long. Like other grasses, the leaves also have parallel venation.

Distribution

''Cymbopogon citratus'' is native to Island Southeast Asia (

Malesia Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalayan and Australasian realms, and also a phytogeographical floristic region in the Paleotropical Kingdom. It has been given different definitions. Th ...

). It has been introduced extensively to

South Asia South Asia is the southern subregion of Asia, which is defined in both geographical Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth descr ...

since precolonial times. After the

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

, lemongrass was introduced to

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

, and

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

. It has now been naturalized throughout the tropics and subtropics worldwide. In its native range, ''Cymbopogon citratus'' is known as ''sereh'', ''serai'', or ''serai dapur'' in

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

and

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

; and ''tanglad'' (from

Proto-Austronesian Proto-Austronesian (commonly abbreviated as PAN or PAn) is a proto-language. It is the reconstructed ancestor of the Austronesian languages, one of the world's major language families. Proto-Austronesian is assumed to have begun to diversify ...

*''Caŋelaj'' originally referring to '' Themeda gigantea'', a type of elephant grass), ''salai'', or ''balioko'' in the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

Culinary uses

Lemongrass sold at a supermarket in the Philippines

''Cymbopogon citratus'' is abundant in the

and

where it is known as ''tanglad'' or ''sereh'' respectively Its fragrant leaves are traditionally used in cooking, particularly for ''

lechon A suckling pig is a piglet fed on its mother's milk (i.e., a piglet which is still a " suckling"). In culinary contexts, a suckling pig is slaughtered between the ages of two and six weeks. It is traditionally cooked whole, often roasted, ...

'' and roasted chicken. The dried leaves can also be brewed into a tea, either alone or as a flavoring in other teas, imparting a flavor reminiscent of lemon juice but with a mild sweetness without significant sourness or tartness. In Sri Lanka, lemongrass is known as ''sera'' (සේර). It is used as a herb in cooking, in addition to its use for the essential oils. Lemongrass in Thailand is called ''takhrai'' (ตะไคร้). It is the essential ingredient of ''

tom yam Tom yum or tom yam (, ; th, ต้มยำ, ) is a type of hot and sour Thai soup, usually cooked with shrimp (prawn). The words "tom yam" are derived from two Thai words. ''Tom'' refers to the boiling process, while ''yam'' means 'mixed'. ...

'' and '' tom kha kai''. Fresh thin slices of lemongrass stem also used in miangpla, as a snack food.

Medicinal uses

The leaves of ''Cymbopogon citratus'' have been used in traditional medicine and are often found in herbal supplements and teas. Evidence of effective ''Cymbopogon citratus'' essential oil anti-protozoa activity against ''Leishmania amazonensis''.

Chemical composition

Lemon grass oil contains 65–85%

citral Citral is an acyclic monoterpene aldehyde, and being a monoterpene, it is made of two isoprene units. Citral is a collective term which covers two geometric isomers that have their own separate names; the ''E''-isomer is named geranial (''trans' ...

in addition to

myrcene Myrcene, or β-myrcene, is a monoterpene. A colorless oil, it occurs widely in essential oils. It is produced mainly semi-synthetically from '' Myrcia'', from which it gets its name. It is an intermediate in the production of several fragrances. ...

citronellal Citronellal or rhodinal ( C10 H18 O) is a monoterpenoid aldehyde, the main component in the mixture of terpenoid chemical compounds that give citronella oil its distinctive lemon scent. Citronellal is a main isolate in distilled oils from the p ...

citronellol Citronellol, or dihydrogeraniol, is a natural acyclic monoterpenoid. Both enantiomers occur in nature. (+)-Citronellol, which is found in citronella oils, including ''Cymbopogon nardus'' (50%), is the more common isomer. (−)-Citronellol is w ...

linalool Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of ...

and

geraniol Geraniol is a monoterpenoid and an alcohol. It is the primary component of citronella oil and is a primary component of rose oil, palmarosa oil. It is a colorless oil, although commercial samples can appear yellow. It has low solubility in w ...

. Hydrosteam distillation, condensation, and cooling can be used to separate the oil from the water. The hydrosol, as a by-product of the distillation process, is used for the production of skin care products such as lotions, creams, and facial cleansers. The main ingredients in these products are lemon grass oil and "negros oil" (mixture of lemon grass oil with virgin coconut oil) used in

aromatherapy Aromatherapy is based on the usage of aromatic materials including essential oils and other aroma compounds, with claims for improving psychological and physical well-being. It is offered as a complementary therapy or as a form of alternative ...

Citronellol Citronellol, or dihydrogeraniol, is a natural acyclic monoterpenoid. Both enantiomers occur in nature. (+)-Citronellol, which is found in citronella oils, including ''Cymbopogon nardus'' (50%), is the more common isomer. (−)-Citronellol is w ...

is an essential oil constituent from ''Cymbopogon citratus'', ''Cymbopogon winterianus'', and ''Lippia alba''. Citronellol has been shown to lower blood pressure in rats by a direct effect on the vascular smooth muscle leading to vasodilation. In a small, randomized, controlled trial, an infusion made from ''C. citratus'' was used as an inexpensive remedy for the treatment of oral thrush in HIV/AIDS patients. Laboratory studies have shown cytoprotective, antioxidant, and anti-inflammatory properties ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called " test-tube experiments", these studies in biology ...

''.

Traditional medicinal use

In the

folk medicine Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...

of the

Krahô The Krahô (, ) are an indigenous Timbira Gê people of northeastern Brazil. The Krahô historically inhabited a portion of modern Maranhão along the Balsas River, but were pushed west by pioneer settlement and cattle farmers. Currently, the Kr ...

people of Brazil, it is believed to have anxiolytic, hypnotic, and anticonvulsant properties.Rodrigues, Eliana & Carlini, E.A. (2006): Plants with possible psychoactive effects used by the Krahô Indians, Brazil. ''Revista Brasileira de Psiquiatria'' 28(4): 277-282
PDF fulltext
In

traditional medicine Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

the leaves of the plant are used as stimulant,

sudorific Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distribu ...

, antiperiodic, and anticatarrhal, while the essential oil is used as carminative,

depressant A depressant, or central depressant, is a drug that lowers neurotransmission levels, which is to depress or reduce arousal or stimulation, in various areas of the brain. Depressants are also colloquially referred to as downers as they lower the ...

, analgesic, antipyretic, antibacterial, and antifungal agent.

Effect on insects

Beekeeper A beekeeper is a person who keeps honey bees. Beekeepers are also called honey farmers, apiarists, or less commonly, apiculturists (both from the Latin '' apis'', bee; cf. apiary). The term beekeeper refers to a person who keeps honey bees i ...

s sometimes use lemon grass oil in swarm traps to attract swarms. Lemon grass oil has also been tested for its ability to repel the pestilent stable fly, which bite domestic animals.

References

External links

''Cymbopogon citratus'' List of Chemicals (Dr. Duke's)''Cymbopogon citratus'' from the Biodiversity Heritage Library'Citronella – anticeptic and anti-inflammation' in Vietnam botanical life
{{Taxonbar, from=Q33913 citratus Grasses of India Flora of Nepal Flora of Sri Lanka Medicinal plants of Asia Anxiolytics Antidepressants Beekeeping Herbs Plants described in 1906