Coriander is related to parsley and carrots. All parts of the plant are edible. The fresh leaves (which should be called cilantro to avoid confusion) and the dried seedpods are the parts most commonly used in cooking. This article refers to the "seeds" (botanically the fruit) of the coriander plant. See the cilantro article if a recipe specifies coriander leaves or if it specifies fresh coriander but not fresh coriander seeds. In such cases, please adjust the recipe to avoid confusion.
The seeds have a lemon citrus flavor when crushed. It is also described as warm, nutty, spicy, and orange-flavoured. The seeds are usually dried but can be eaten green. Ground coriander is a major ingredient in curry powder and other aromatic dishes.
If the spice is bought whole in a non-dried form, it can be dried in the sun. Most commonly, it is bought as whole dried seeds, or in ground form. If whole, it can be roasted or heated on a dry pan briefly to enhance the aroma before grinding it in an electric grinder or with a mortar and pestle. Store coriander in a tightly sealed container away from sunlight and heat. For maximum flavour use within 6 months and keep for no more than 1 year.