Arctium lappa

Arctium lappa, commonly called greater burdock, gobō (牛蒡/ゴボウ), edible burdock, lappa, beggar's buttons, thorny burr, or happy major is a Eurasian species of plants in the Aster family, cultivated in gardens for its root used as a vegetable. It has become an invasive weed of high-nitrogen soils in North America, Australia, and other regions. Greater burdock is a biennial plant, rather tall, reaching as much as 3 m (10 ft). It has large, alternating, cordiform leaves that have a long petiole and are pubescent on the underside. The flowers are purple and grouped in globular capitula, united in clusters. They appear in mid-summer, from July to September. The capitula are surrounded by an involucre made out of many bracts, each curving to form a hook, allowing the mature fruits to be carried long distances on the fur of animals. The fruits are achenes; they are long, compressed, with short pappus hairs. These are a potential hazard for humans, horses, and dogs. The minute, sharply-pointed, bristly pappus hairs easily detach from the top of the achenes and are carried by the slightest breeze – attaching to skin, mucous membranes, and eyes where they can cause severe dermal irritation, possible respiratory manifestations, and ophthalmia. The fleshy tap-root can grow up to 1 m (3 ft 3 in) deep. 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 India, China, Taiwan and Japan. 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. The leaves of greater burdock provide food for the caterpillars of some Lepidoptera, such as the thistle ermine (Myelois circumvoluta). 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 sowing the seeds midsummer. The harvest occurs three to four months after the seeding until late autumn, when the roots become too fibrous. Greater burdock root is known as niúbàng (牛蒡) in Chinese, which was borrowed into Japanese as gobō and Korean as ueong (우엉), and is widely eaten in Japan, Korea and Taiwan. It was used in Europe during the Middle Ages as a vegetable, but now it is rarely used except in Italy, Brazil and Portugal, where it is known as bardana or 'garduna'. Plants are cultivated for their slender roots, which can grow about 1 meter long and 2 cm across. The root was traditionally used in Britain as a flavouring in the herbal drink dandelion and burdock, which is still commercially produced.