Xiang Yuan

Citrus medica L. (Rutaceae), the citron, is a small, irregularly shaped evergreen tree or shrub 2-5 m tall with stout, angular, often spiny young branches and large, oblong-ovate, leathery leaves bearing translucent oil glands and indistinctly winged petioles. Fragrant, white to purplish-tinged flowers in axillary clusters give rise to large, ovoid to oblong fruits 10-25 cm long with a very thick, bumpy, fragrant yellow rind and sparse, sour or sweet pulp. Closely related cultivars and Citrus wilsonii Tanaka are also accepted sources of the Chinese drug Xiang Yuan. Native to northeast India and adjacent Himalayan foothills and cultivated since antiquity, the dried mature fruit is used in TCM to regulate qi, harmonize the Stomach, and resolve phlegm.