Yuan Zhi

Polygala tenuifolia

Physical Characteristics

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.

Distribution

E. Asia - Korea, Mongolia, Manchuria.

Habitats

Cultivated Beds;

Edible Uses

Edible Parts: Leaves Root Edible Uses: Young leaves - cooked[105, 177, 179]. Root - cooked[105, 177]. The core is removed and the root is boiled in several changes of water[179].

Medicinal Uses

Cardiotonic Expectorant Haemolytic Kidney Sedative Tonic 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[254]. The root is antibacterial, cardiotonic, cerebrotonic, expectorant, haemolytic, hypotensive, sedative and tonic[116, 147, 176, 218]. It acts mainly as a tonic for the heart and kidney energies[238]. It is taken internally in the treatment of coughs with profuse phlegm, bronchitis, insomnia, palpitations, poor memory, anxiety, depression and nervous tension[238]. Externally it is used to treat boils and carbuncles[147, 238]. The root is harvested in the autumn and dried for later use[238]. The leaves are used as a tonic for the kidneys[218].

Known Hazards

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.