Cilantro is an herb from the fresh leaves of the coriander plant (Coriandrum sativum). This plant is a member of the parsley family, and the herb is also known as Chinese parsley and Mexican parsley. In the U.K. and some other places, you will see cilantro called fresh coriander leaves. The leaves look much like flat-leaf parsley, growing on long, tender stems. The seeds of the plant are used to make coriander spice, which has a completely different flavor from cilantro. The roots of the plant are also edible and used in some dishes.