Lemongrass
A tall tropical grass whose pale lower stalk gives lemon-like freshness to Southeast Asian food.
Also: sera, takrai, serai, gandhatrina
Lemongrass is the stalk of Cymbopogon citratus, a clumping grass of South and Southeast Asia. The lower bulb carries citral, the same aroma compound as lemon peel, and tastes lemony yet floral and mildly grassy. Cooks bruise or finely slice it for Thai tom yum, Vietnamese grilled meats, Indonesian curries and Sri Lankan dishes, and use the outer leaves in tea. The tough upper blade is too fibrous to eat but can flavour broths. It grows easily in warm climates and lasts well in the freezer. It is a seasoning from a plant, not a dried spice, but it plays the same role.