
Lemongrass stem is the tender lower stalk of Cymbopogon citratus, a tropical grass used fresh as a lemon-scented culinary aromatic.
Bright, fresh and distinctly lemony on the nose, delivering lemon character without any of the fruit's sourness.
Bruise, crush, or finely slice the stem to release its oils — a whole unbruised stalk contributes little — then infuse it as an aromatic; a defining lemon note rather than a source of acidity or body.
As a background accent its loss is tolerable, but as the leading aromatic it is essentially not substitutable — only another citral-bearing aromatic can approximate the bright lemon-without-sourness profile, while any lemon note that relies on the fruit's acid cannot reproduce it.
East Indian lemongrass
C. citratus (West Indian lemongrass) is the species used culinarily and as the stem aromatic, whereas C. flexuosus is grown chiefly for perfumery and citral extraction; both share the citral-driven lemon aroma and are sometimes used interchangeably.
Citronella grass
Citronella grasses (Cymbopogon nardus / winterianus) are distinct species of the same genus grown for citronella oil used in soaps and insect repellents, not as a culinary stem, despite a shared citrus-like aroma.
Growers harvest the stalks of Cymbopogon citratus, a perennial grass of the family Poaceae, and sell the lower stem as an aromatic. Only the tender base carries concentrated essential oil dominated by citral (the isomers geranial and neral); the tough outer layers and upper stalk are typically bruised for infusion and then discarded.
Citral oxidizes readily, so the bright top notes fade on drying and storage; keep stems fresh and use them promptly, as fresh gives a markedly brighter aroma than dried.
Cymbopogon citratus is native to South Asia and Maritime Southeast Asia, where the stem is a staple aromatic of Southeast Asian cuisines such as Thai and Vietnamese cooking.