An Introduction to the Benefits, Uses and Cultivation Tips of Evodia lepta

Evodia lepta is an evergreen shrub or small tree in the Rutaceae family. It gets its name because each compound leaf is made up of three leaflets and the branches divide into three like a fork; in folk usage it is also often written as Sanya ku, and it has other aliases such as Sanzhi qiang. It is mainly distributed across the warm, humid hills and mountains of southern China, and is mostly seen beside valley streams, at forest edges or beneath open woodland; it likes light but also tolerates a little shade.

In appearance, the bark of Evodia lepta is greyish white or greyish brown, the leaflets are opposite and nearly papery in texture, give off a distinct aroma when crushed, and taste bitter. The flowers are small and yellow-white, mostly opening in spring and summer; when the fruit ripens the rind splits open to reveal the seeds, giving the plant fairly high overall recognisability.

In terms of useful value, the dried leaves, tender branches and roots of Evodia lepta can all be used as medicine. Its nature and flavour are bitter and cold, and traditional medicine holds that it clears heat and resolves toxin and dispels wind and dampness, and it is often used as an adjunctive treatment for problems such as colds with fever, sore and swollen throat, rheumatic bone pain and skin eczema. In the Lingnan region it is also a common ingredient in herbal cooling teas and some Chinese patent medicines for colds.

Cultivation of Evodia lepta generally uses seed propagation. It is best to choose sandy loam with deep soil and good drainage, and to transplant at the right time after raising seedlings; during the growing period, keep the soil moist and weed and apply supplementary fertiliser in good time. When harvesting for medicinal use, the branches and leaves are usually cut in summer and autumn, then sun-dried or shade-dried and stored in a dry, well-ventilated place; simply take care to prevent damp and mould.