Geography and distribution
Lemon grass is native to Indonesia, and introduced and cultivated in most of the tropics, including Africa, South America and Indo-China.
Overview: A tall, aromatic, perennial grass with culms (stems) up to 2 m tall.
Leaves: Linear, up to 1 m long and 2 cm wide, tapering towards the sheath. They are smooth and hairless, white on the upper surface and green beneath. The ligules (appendage between the leaf sheaf and blade) are less than 2 mm long, and are rounded or truncate (ending abruptly as if cut off).
Flowers: The inflorescence is a loose, nodding panicle, about 60 cm long and reddish to russet in colour. The pedicels (stalks of the spikelets) are tinged with purple.
Threats and conservation
There are no known direct threats to this species. It is widely distributed and populations are considered to be stable.
Conservation assessments carried out at Kew
Cymbopogon citratus is being monitored as part of the IUCN Sampled Red List Index for Plants, which aims to produce conservation assessments for a representative sample of the world’s plant species. This information will then be used to monitor trends in extinction risk and help focus conservation efforts where they are needed most.
Learn more about this project
The culms (stems) of lemon grass are widely used in teas and other beverages, herbal medicines, and to flavour southeast Asian cuisine, particularly fish stews and sauces.
Culms (stems) of lemon grass (Photo: Wolfgang Stuppy)
Lemon grass is also grown in pots indoors, to provide rooms with its ‘fresh’ fragrance.
Cymbopogon citratus is closely related to C. nardus, the species of grass from which the insect-repellent citronella is derived. The oil extracted from lemon grass has also been used as an insect-repellent, as well as to perfume beauty products.
Lemon grass is planted on bunds (embankments or dikes) in south and southeast Asia for soil conservation, and is excellent as a mulch.
Lemon grass at Kew
Lemon grass can be seen growing in the Waterlily House at Kew.
Specimens of lemon grass, including dried leaves and oil, are held in Kew's Economic Botany Collection, and are available to researchers by appointment.
The Danish botanist Nathaniel Wallich reported in 1832 (in Plantae Asiaticae Rariores) that “Dr Maton, physician to Queen Charlotte, has repeatedly been treated with a dish of lemon grass tea by Her Majesty who used to be very fond of it and was supplied with the plant from the Royal Gardens at Kew.”
Pivotal work on ‘oil-grasses’
An extensive and much-needed revision of the systematics of the plants collectively known as ‘oil-grasses’ (Cymbopogon spp., Chrysopogon (incl. Vetiveria) spp. and Andropogon spp.) was conducted by the Austrian botanist Otto Stapf whilst he was Principal Assistant in the Herbarium at Kew, and published in Kew Bulletin in 1906. Three years later he became Keeper of the Herbarium.