Sawtooth coriander is a long slender herb with jagged edged leaves, hence its name sawtooth coriander. It is also known as Culantro, and is commonly used in Vietnamese and Thai cooking. Its flavor is similar to that of coriander, but stronger in intensity and pepperiness. You can find it Vietnamese or Thai specialty ingredient stores. After purchasing, store in a tall mason jar filled with one to two inches of water. Cover the jar with a ziplock bag and seal it at the base with a rubber band.