Cymbopogon citratus
Lemon grass is a perennial edible grass with lemon-scented leaves. The stalk is used in Thai curry pastes, soups, marinades, sauces and tea. 
Size: 1-1.5m H - will continue clumping
Light: Full sun to part shade
Care: Warm, sunny position with well-drained soil. Keep well watered throughout the hotter months.