Sereh от John Spottiswood

Thai cooks use these grayish green stalks to impart a lemony flavor to their dishes. Remove the outer leaves, then use about six inches of the base, discarding the top and the very bottom. It's best to cut lemongrass into large pieces that can be easily removed after the dish is cooked. Frozen lemongrass is a good substitute for fresh, but dried lemongrass (soaked in hot water) is only a fair substitute. Use powdered version (called sereh powder) only in a pinch.