Tian Nan Xing
Botanical name: Arisaema amurense
Common name: Arisaema rhizome, Jack-in-the-pulpit
Literal name translation: star of southern heavens
Part used in Chinese medicine: prepared rhizome
Major Chinese medicine actions:
Dries dampness, expels phelgm, disperses wind-phlegm,
stops spasms, alleviates pain, reduces swelling
Photo 1: Arisaema fargesii; International Aroid Society author unknown
Photo 2: Arisaema amurense; International Aroid Society author unknown
Photo 3: Arisaema yunanense; International Aroid Society author unknown
Photo 4: Arisaema amurense; International Aroid Society author unknown
Arisaema, commonly known as Jack-in-the-Pulpit, is a perennial woodland plant often cultivated for its quite unusual tubular flowers, called "spathes". The plants are unique in many ways. Some are male, some are female, some are both, and some change back and forth (paradioecious). In general, arisaemas are male when young and when they build up enough energy to have babies, they switch and become female. The year after giving birth (fruiting), they will often revert back to being male.
There are many acceptable species grown for use in Chinese medicine as the herb Tian Nan Xing, including Arisaema erubescens, A. heterophyllum, A. amurense, A. lobatum. A. yunanense, A. lichingense, A. elephas, A. angustatum, A. fargesii, and A. flavum.
Growing and Propagation
Generally arisaema grows best in part shade or dappled shade, and in well-drained, humus-rich soil. They should be planted quite deeply, to about 12 inches, and often need protection from slugs. Plants must have good drainage so they do not rot during the winter due to water-logging. Flowers appear from April to May. Arisaema grows in USDA zones 4-9, to temperatures as low as -30 degrees F.
In order to propagate arisaema, seed is needed from both a male and female plant. After harvesting the seeds, they must be cleaned as the pulp contains a germination inhibitor. The ripened seed can be placed in a plastic bag and mashed until the pulp separates from the seed, then washed until seeds are clean.
Seeds can be difficult to germinate in a greenhouse or indoors and should be stratified prior to planting in moistened growth medium in a plastic bag. The bag should be kept in the refrigerator for about 6 weeks before the seed is sown in pots and germinated. They will usually sprout in 1-6 months. The plants will grow for a few months before turning yellow and becoming dormant. During their dormancy, they should be kept fairly dry, watering only about once every two weeks, when completely dry. Plants will sprout again in the spring or fall and can be planted outdoors. When grown from seed, the plants take 2-4 years to flower.
Some arisaema species multiply by offsets, and the small bulblets or runners can be removed and replanted in the fall. Arisaema candidissimum, A. amurense, A. concinnum, A. costatum, A. exappendiculatum, A. ringens, and A. ternatipartitum are good candidates for this method of propagation. Plants can be divided in the late winter.
Harvesting and Processing
For medicinal use, good quality raw herb is harvested in the fall and consists of large, white rhizomes. The raw, unprocessed root of arisaema is toxic, therefore when the herb is used medicinally it is generally processed. Tian Nan Xing usually refers to Zhi Tian Nan Xing, or processed Tian Nan Xing. In this case the cleaned raw herb is soaked and washed several times, then soaked for a day in water with alum added. After washing again, the herb is boiled in water with ginger and alum until the center is no longer dry. The herb is partially dried, then sliced and dried completely.
The raw herb may also be processed with bile, called Dan Nan Xing. In this case the prepared arisaema (Zhi Tian Nan Xing) is powdered and mixed with sterilized pig, cow or sheep bile, then steamed for one hour. After cooling, it is cut into small cubes and dried. The quality of Dan Nan Xing is considered best after being stored for some time, and is sometimes known as Chen Dan Xing ("old" Dan Xing).