Yuan Zhi
Polygala tenuifolia
Family: Polygalaceae
What it is like
Polygala tenuifolia is a PERENNIAL growing to 0.2 m (0ft 8in) by 0.2 m (0ft 8in). See above for USDA hardiness. It is hardy to UK zone 6. The species is hermaphrodite (has both male and female organs). Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.
Height (m): 0.2
Where it is found
Hillsides, roadsides and meadows. Dry meadows and stony slopes.
E. Asia - Korea, Mongolia, Manchuria.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
Young leaves - cooked. Root - cooked. The core is removed and the root is boiled in several changes of water.
Root: includes bulbs, corms, tubers, rhizomes etc.
Medicine
Rating: 3
Yuan Zhi contains triterpenoid saponins, these promote the clearing of phlegm from the bronchial tubes. The plant is used mainly as an expectorant and stimulant to treat bronchial asthma, chronic bronchitis and whooping cough. The root is antibacterial, cardiotonic, cerebrotonic, expectorant, haemolytic, hypotensive, sedative and tonic. It acts mainly as a tonic for the heart and kidney energies. It is taken internally in the treatment of coughs with profuse phlegm, bronchitis, insomnia, palpitations, poor memory, anxiety, depression and nervous tension. Externally it is used to treat boils and carbuncles. The root is harvested in the autumn and dried for later use. The leaves are used as a tonic for the kidneys.
Cardiotonic: A tonic for the heart.
Expectorant: Clears phlegm from the chest by inducing coughing.
Haemolytic: Breaks down red blood corpuscles to separate haemoglobin.
Kidney: Used in the treatment of kidney diseases
Sedative: Gently calms, reducing nervousness, distress and irritation.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Other
Rating:
How it is grown
Prefers a moderately fertile moisture-retentive well-drained soil, succeeding in full sun if the soil remains moist throughout the growing season, otherwise it is best in semi-shade. Dislikes shade according to another report. Plants are hardy to at least -15°c.
Propagating it: Seed - sow spring or autumn in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Division. Cuttings of young shoots in a frame in late spring.
Best place to grow: Cultivated Beds;
Habit: Perennial
Hardiness: 5-9
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist
Things to keep in mind
Although no specific mention has been seen for this species, at least one member of this genus is said to be poisonous in large quantities.