By Harold McGee
Perilla is the leaf of Perilla frutescens, a mint relative native to China and India. It was taken to Japan in the 8th or 9th century and named shiso; many Westerners get their first taste of it in sushi restaurants. The distinctive aroma of perilla is due to a terpene called perillaldehyde, which has a fatty, herbaceous, spicy character. There are several different perilla varieties, some green, some red to purple with anthocyanins, some with no perillaldehyde and instead tasting of dill or lemon. The Japanese eat the leaves and flower heads with seafood and grilled meats, and use a red variety to color and flavor the popular pickled plum, umeboshi. Koreans obtain both flavor and cooking oil from perilla seeds.