Lemongrass is a common ingredient in Southeastern Asian cooking, prized for its green, slightly lemon-like flavor. In some African traditions, Lemongrass tea is common; whereas in other parts of the world the oil can be used as a mosquito repellant and honey bee attractant.
In gin, lemongrass can sometimes come through with a citrusy note, adding some greenness to it. And I often find it to taste similar to lemon verbena and other citrus-scented grasses when distilled. It’s become quite popular since 2012 in gins which often are looking to impart an “Asian”-inspired approach, most notably the launch of Bombay Sapphire East which featured lemongrass along with black pepper.