Zi Su Zi

Perilla frutescens (Zi Su Zi when referring to the seed; the leaf is Zi Su Ye) is an aromatic annual herb in the Lamiaceae family, typically growing 30 to 100 centimeters tall, with quadrangular, often purple-tinged stems and opposite, broadly ovate leaves 7 to 12 centimeters long, coarsely serrate with pointed tips and frequently flushed purple on one or both surfaces. The whole plant emits a pungent, characteristic aroma reminiscent of basil and anise. Small white to pinkish-purple flowers are borne in dense terminal and axillary racemes through late summer, each subtended by a persistent calyx that enlarges in fruit. The fruits are small grayish-brown to dark brown nutlets about 1 to 2 millimeters in diameter, four contained within each persistent calyx, with a reticulate surface and oily contents rich in alpha-linolenic acid. Native to East and Southeast Asia, Perilla frutescens has long been cultivated for culinary and medicinal use across China, Korea, and Japan, and has naturalized widely.