Dill (Anethum graveolens) is a feathery annual of the carrot family whose soft, thread-fine blue-green fronds carry a fresh, sweet-grassy aroma — part anise, part caraway, part bright citrus and cut grass. Native to the eastern Mediterranean and West Asia, it has become the signature green of a broad band of cooking running from Scandinavia through Eastern Europe and Russia to the Levant. The whole plant is fragrant, but it gives two distinct seasonings: the delicate "dill weed" of the leaves, central to gravlax, tzatziki and soured-cream sauces, and the warmer, more caraway-like dill seed used above all in pickling. It is the defining note of a dill pickle, and a herb so volatile that it is almost always added raw or at the very last moment.