Greater burdock

Overview
Greater burdock, Edible burdock, or Lappa Burdock is a biennial plant of the Arctium (burdock) genus in the Asteraceae family, cultivated in gardens for its root used as a vegetable.

Description
Greater Burdock is rather tall, reaching as much as 2 metres. It has large, alternating, cordiform leaves that have a long petiole petiole and are pubescent on the underside.

The flowers are purple and grouped in globular capitula, united in clusters. They appear in mid-summer. The capitula are surrounded by an involucre made out of many bracts, each curving to form a hook, allowing them to be carried long distances on the fur of animals. The fruits are achenes; they are long, compressed, with short pappuses.

The fleshy tap-root can grow up to 1m long.

Origin and distribution
This species is native to the temperate regions of the old world, from Scandinavia to the Mediterranean, and from the British Isles through Russia, and the Middle East to China and Japan, including India. It is naturalized almost everywhere and is usually found in disturbed areas, especially in soil rich in nitrogen. It is commonly cultivated in Japan where it gives its name to a particular construction technique, burdock piling.

Cultivation
It prefers a fresh, worked soil, rich in humus, and should be positioned in full sunlight. Burdock is very reactive to nitrogen fertilizer. Propagation is achieved through direct sowing the seeds midsummer. The harvest occurs three to four months after the seeding until late autumn, when the roots become too fibrous.

Use in traditional medicine
Folk herbalists consider dried burdock to be a diuretic, diaphoretic, and a blood purifying agent. The seeds of greater burdock are used in traditional Chinese medicine, under the name niupangzi .