A tropical grass that smells of lemon without ever having seen a lemon tree — thanks to a molecule called citral.

What is lemongrass?

Lemongrass is a tall perennial grass of the genus Cymbopogon, a relative of citronella and palmarosa. Two species are cultivated: East Indian lemongrass (Cymbopogon flexuosus) and West Indian lemongrass (Cymbopogon citratus), familiar from Thai cooking. The essential oil is steam-distilled from the fresh or partly dried leaves and is 70–85% citral — the blend of geranial and neral that gives the intensely lemony scent — with geraniol, myrcene and limonene. Cosmetics use the essential oil and the ground leaves.

What are the benefits of lemongrass?

Lemongrass is “greener” and earthier than lemon, with a grassy, slightly gingery base. In skin care:

• Scents with a fresh, grassy-lemony note
• Has a toning, astringent feel
• Suits skin and scalp with a tendency to oiliness
• Gives a feeling of cleanliness and freshness
• Offers antioxidant constituents such as citral and geraniol

The molecule that smells of lemon

Citral is one of the most important molecules in perfumery: it is the same substance that gives the lemony note to lemon, lemon verbena, lemon balm and ginger, and from it the ionones — the scent of violets — and vitamin A are made. Lemongrass is its richest natural source. Like most natural fragrance constituents, citral is listed separately among the ingredients (Citral), because it belongs to the fragrance allergens that must be declared.

Where does it come from?

Lemongrass originates in South and South-East Asia. The East Indian species is grown mainly in India (Kerala, Assam) and Sri Lanka, the West Indian species in Guatemala, Brazil, Thailand and Vietnam.