Zao Jiao Ci
Botanical name: Gleditsia sinensis
Common name: Gleditisia thorn
Literal name translation: soap horn thorn
Family: Fabaceae, pea family
Part used in Chinese medicine: thorn
Major Chinese medicine actions:
Draws out toxicity, discharges pus, invigorates blood,
Photo 1: Gleditsia sinensis; 10/2004, author Kurt Stueber; permission under GFDL
Photo 2: Gleditsia sinensis; 10/2004, author Kurt Stueber; permission under GFDL
Zao Jiao Ci is a medium growing deciduous tree native to western China. It grows about 12 feet high and has unusual thorny protrusions than grow from its trunk.
Growing and Propagation
Though somewhat tender when young, the tree requires full sun, grows easily in most soils, and is drought tolerant. If growing from seed, they should be pre-soaked for 24-48 hours in warm water until swollen. Scarification with a file, then soaking, also helps promote seed germination, which should occur within 2-4 weeks. Cuttings may also be used to propagate the plant, using half-woody young branches 4-6 inches long. Planting in a bed of chaff ash may promote successful rooting.
Gleditisia should be grown in a greenhouse until established, then planted outside in a permanent location. The plants are hardy to USDA zone 5, but should be protected from the cold for their first few winters outdoors.
Harvesting and Preparation
For medicinal use, good quality Zao Jiao Ci consists of large, solid thorns that are purplish brown in color.