Plants of the genus Arctium have dark green leaves that can grow up to 28" (71 cm) long. They are generally large, coarse and ovate, with the lower ones being heart-shaped. They are woolly underneath. The leafstalks are generally hollow. Arctium species generally flower from July through to October.
The prickly heads of these plants (burrs) are noted for easily catching on to fur and clothing (being the inspiration for Velcro), thus providing an excellent mechanism for seed dispersal. Burrs cause local irritation and can possibly cause intestinal hairballs in pets. However, most animals avoid ingesting these plants.
A large number of species have been placed in genus Arctium at one time or another, but most of them are now classified in the related genus Cousinia. The precise limits between Arctium and Cousinia are hard to define; there is an exact correlation between their molecular phylogeny. The burdocks are sometimes confused with the cockleburs (genus Xanthium) and rhubarb (genus Rheum).
The roots of burdock, among other plants, are eaten by the larva of the Ghost Moth (Hepialus humuli). The plant is used as a food plant by other Lepidoptera including Brown-tail, Coleophora paripennella, Coleophora peribenanderi, the Gothic, Lime-speck Pug and Scalloped Hazel.
The green, above-ground portions may cause contact dermatitis in humans due to the lactones the plant produces.
Food and drinkThe taproot of young burdock plants can be harvested and eaten as a root vegetable. While generally out of favour in modern European cuisine, it remains popular in Asia. In Japan, A. lappa (Greater burdock) is called "gobō" (牛蒡 or ごぼう); in Korea burdock root is called "u-eong" (우엉) and sold as "tong u-eong" (통우엉), or "whole burdock". Plants are cultivated for their slender roots, which can grow about 1 metre long and 2 cm across. Burdock root is very crisp and has a sweet, mild, and pungent flavour with a little muddy harshness that can be reduced by soaking julienned or shredded roots in water for five to ten minutes. Immature flower stalks may also be harvested in late spring, before flowers appear; their taste resembles that of artichoke, to which the burdock is related. Leaves are also eaten in springs in Japan when a plant is young and leaves are soft. Some A. lappa cultivars are specialized in this purpose. A popular Japanese dish is kinpira gobō (金平牛蒡), julienned or shredded burdock root and carrot, braised with soy sauce, sugar, mirin and/or sake, and sesame oil; another is burdock makizushi (sushi filled with pickled burdock root; the burdock root is often artificially coloured orange to resemble a carrot).
In the second half of the 20th century, burdock achieved international recognition for its culinary use due to the increasing popularity of the macrobiotic diet, which advocates its consumption. It contains a fair amount of dietary fiber (GDF, 6g per 100g), calcium, potassium, amino acids, and is low in calories. It contains a polyphenol oxidase, which cause its darkened surface and muddy harshness by forming tannin-iron complexes. Burdock root's harshness harmonizes well with pork in miso soup (tonjiru) and with Japanese-style pilaf (takikomi gohan).
Dandelion and burdock is today a soft drink that has long been popular in the United Kingdom, which has its origins in hedgerow mead commonly drunk in the medieval period. Burdock is believed to be a galactagogue, a substance that increases lactation, but it is sometimes recommended to be avoided during pregnancy based on animal studies that show components of burdock to cause uterus stimulation.
In parts of the US (notably western New York), burdock stalks are eaten as a substitute for cardoon. The stalks are peeled, scrubbed, boiled in salt water, and fried in an egg and breadcrumb batter.
Traditional medicineFolk herbalists consider dried burdock to be a diuretic, diaphoretic, and a blood purifying agent. The seeds of A. lappa are used in traditional Chinese medicine, under the name niupangzi (Chinese: 牛蒡子; pinyin: niúpángzi; Some dictionaries list the Chinese as just 牛蒡 niúbàng.)
Burdock is a traditional medicinal herb that is used for many ailments. Burdock root oil extract, also called Bur oil, is popular in Europe as a scalp treatment applied to improve hair strength, shine and body, help reverse scalp conditions such as dandruff, and combat hair loss. Modern studies indicate that burdock root oil extract is rich in phytosterols and essential fatty acids (including rare long-chain EFAs), the nutrients required to maintain a healthy scalp and promote natural hair growth. It combines an immediate relieving effect with nutritional support of normal functions of sebaceous glands and hair follicles According to some European herbalists, combining burdock root oil with a nettle root oil and massaging these two oils into the scalp every day has a greater effect than Bur oil alone.
Burdock leaves are used by some burn care workers for pain management and to speed healing time in natural burn treatment. Burn care workers hold that it eases dressing changes and appears to impede bacterial growth on the wound site and that it also provides a great moisture barrier.
French ClothIn the early 1700s, Frenchmen introduced these by the thousands into North America. They used it exclusively as a cotton twill. But once the cotton gin was invented, the Frenchmen left, and the burdock spread incredibly quickly. The Frenchmen left during the windy season, and it spread even more. Burdock is considered an invasive species in North America.
Burdock and VelcroAfter taking his dog for a walk one day in the early 1940s, George de Mestral, a Swiss inventor, became curious about the seeds of the burdock plant that had attached themselves to his clothes and to the dog's fur. Under a microscope, he looked closely at the hook-and-loop system that the seeds use to hitchhike on passing animals aiding seed dispersal, and he realised that the same approach could be used to join other things together. The result was Velcro.
TolstoyThe Russian writer Leo Tolstoy wrote in his journal, in 1896, about a tiny shoot of burdock he saw in a ploughed field, "black from dust but still alive and red in the center … It makes me want to write. It asserts life to the end, and alone in the midst of the whole field, somehow or other had asserted it."
- Arctium lappa : Greater Burdock, Gobō
- Arctium minus : Lesser Burdock, Burweed, Louse-bur, Button-bur
- Arctium minus nemorosum (=Arctium vulgare) : Woodland Burdock, Wood Burdock
- Arctium pubens : Common Burdock
- Arctium tomentosum : Downy Burdock, Woolly Burdock