Cymbopogon is a genus of about 55 species of grasses, native to warm temperate and tropical regions of the Old World and Oceania. It is a tall perennial grass. Common names include lemon grass, lemongrass, barbed wire grass, silky heads, citronella grass, fever grass or Hierba Luisa amongst many others.
Lemon grass is widely used as an herb in Asian (particularly Vietnamese, Hmong, Khmer, Thai, Lao, Malaysian, Indonesian, Philippine, Sri Lankan) and Caribbean cooking. It has a citrus flavour and can be dried and powdered, or used fresh. The stalk itself is too hard to be eaten except for the soft inner part. However, it can be finely sliced and added to recipes. Thai Tom Yum Soup is a very popular dish in Thailand, ingredients of which include thickly cut stalks of lemongrass which give it a very distinct strong flavour. It is also sometimes bruised and added whole as this releases the aromatic oils from the juice sacs in the stalk. The main constituent of lemongrass oil is citral, which makes up around 80% of the total.
Lemon grass is commonly used in teas, soups, and curries. It is also suitable for poultry, fish, and seafood. It is often used as a tea in African and Latino-American countries (e.g., Togo, Mexico, DR Congo).
East-Indian Lemon Grass (Cymbopogon flexuosus), also called Cochin Grass or Malabar Grass, is native to Cambodia, India, Sri Lanka, Burma,and Thailand while the West-Indian lemon grass (Cymbopogon citratus), also known as serai in Malay, is assumed to have its origins in Malaysia. While both can be used interchangeably, C. citratus is more suited for cooking. In India C. citratus is used both as a medical herb and in perfumes.
Lemongrass can also be grown at home by leaving the stalks bought from the market in a small pot of water for two weeks. As soon as little white roots grow, it can be moved to soil.
Research also shows that lemon grass oil has antifungal properties.
Citronella Grass (Cymbopogon nardus and Cymbopogon winterianus) is similar to the species above but grows to 2 m and has red base stems. These species are used for the production of citronella oil, which is used in soaps, as a mosquito repellent in insect sprays and candles, and also in aromatherapy, which is famous in Bintan, Indonesia. The principal chemical constituents of citronella, geraniol and citronellol, are antiseptics, hence their use in household disinfectants and soaps. Besides oil production, citronella grass is also used for culinary purposes, in tea and as a flavoring.
Palmarosa (Cymbopogon martinii), also called Rosha Grass and Indian Geranium, is another species used in the perfume industry. It is a perennial clumping grass which grows to 150 cm with finer leaves and has a smaller bulbous base than the species above. The leaves and flower tops contain a sweet smelling oil which is used for the production of geraniol. It is also distilled into palmarosa oil and used in aromatherapy for its calming effect to help relieve nervous tension and stress.
Lemongrass in some cases has been used as a mild depressant for the central nervous system. It is also sometimes used as a weed barrier.