Zhi Ke (Qiao)

Zhi Ke (枳壳), also transliterated Zhi Qiao, is the dried mature fruit of Citrus × aurantium L. (bitter orange, Rutaceae), harvested when nearly ripe in summer, cut transversely into halves, and sun-dried or low-heat dried. The parent tree is a small, thorny evergreen 3–10 m tall with broadly elliptic, glossy leaves on narrowly winged petioles and fragrant white five-petaled flowers. The fruit is globose to depressed-globose, 4–7 cm across, with a thick, rough, orange to yellow-brown rind, bitter and acidic pulp, and numerous seeds. Cut transverse slices show a thick spongy mesocarp and shrunken radial segments. Zhi Ke is distinguished from Zhi Shi, which is the immature, smaller, more acrid fruit of the same tree harvested in early summer.