Xiang Jia Pi

Xiang Jia Pi is the dried root bark of Periploca sepium Bunge (Apocynaceae, subfamily Asclepiadoideae), a deciduous twining woody vine to small shrub 1-3 m tall, native to northern and central China. The plant bears opposite, lanceolate to ovate-lanceolate leaves 5-9 cm long with acute tips, and produces small star-shaped flowers in lateral cymes with five purplish-brown corolla lobes that are fragrant and recurved. Slender paired follicles 7-12 cm long contain plumed seeds. The root bark is harvested in spring or autumn, dried, and appears as curled quills 3-10 cm long, with a corky, grayish-brown outer surface and yellowish inner surface, with a characteristic aromatic odor. It contains cardenolide glycosides (periplocin, periplocymarin) and is cardiotoxic; modern Pharmacopoeia limits dose strictly and warns against substitution with the safer Wu Jia Pi (Eleutherococcus).