What is burdock? An introduction to the latest burdock knowledge
Burdock, also known as Dali seed, e shi, niubangzi, etc., is a biennial herbaceous plant of the genus Arctium in the Asteraceae family. Its edible value and nutritional value are very high, and it can be stir-fried, boiled, eaten raw, or processed into beverages. In China it is mainly distributed in Taiwan, China, Shandong, Jiangsu, Shaanxi, Henan, Hubei, Anhui, Zhejiang and other places. Feng County and Pei County in Xuzhou, Jiangsu Province, and Cangshan in Shandong Province have a long history of cultivation and relatively large planting areas.
More than a thousand years ago, Japan introduced burdock from China and improved it into a food. When Japan occupied Taiwan, China, it once required local farmers in Tainan to plant it in large quantities. The main reason was that Tainan has sandy loam soil along the Zengwen River, a Tropic of Cancer climate, and the extension of the famous Alishan range, which together created the uniquely precious quality of local burdock. At present, Taiwan, China has used it as a vegetable for many years and is known as the birthplace of burdock.
Burdock has a thick fleshy taproot, up to 15 cm long, with a diameter of up to 2 cm, and has branched lateral roots. The stem is upright, up to 2 m tall, stout, with a basal diameter of up to 2 cm, usually purplish red or pale purplish red, with many raised longitudinal ribs, and the branches are ascending, mostly numerous. All stems and branches are covered with sparse papillate short hairs and long cobwebby hairs mixed with brownish-yellow small glandular dots.
The basal leaves of burdock are broadly ovate, up to 30 cm long and up to 21 cm wide, with sparsely shallow wavy concave teeth or tooth tips at the margin and a heart-shaped base, with petioles up to 32 cm long. The two surfaces are differently colored: the upper surface is green, with sparse short stiff hairs and small yellow glandular dots; the lower surface is grayish white or pale green, covered with thin tomentum or sparse tomentum, and has small yellow glandular dots. The petiole is grayish white, covered with dense cobwebby tomentum and small yellow glandular dots, but often loses hair in the middle and lower parts. The stem leaves are the same shape or nearly the same shape as the basal leaves, with the same kind and amount of indumentum. The leaves near the lower part of the inflorescence are small, with a truncate or shallowly heart-shaped base.
The capitula of burdock are numerous or few, arranged at the tips of stems and branches in loose corymbs or paniculate corymbs, with stout peduncles. The involucre is ovate or ovoid, 1.5-2 cm in diameter. The phyllaries are in many layers, numerous; the outer ones are triangular or lanceolate-subulate, about 1 mm wide; the middle and inner ones are lanceolate or linear-subulate, 1.5-3 mm wide; all involucral bracts are nearly equal in length, about 1.5 cm long, with cartilaginous hooked spines at the apex. The florets are purplish red, the corolla 1.4 cm long, the slender tube 8 mm long, the limb 6 mm long, without glandular dots outside, and the corolla lobes about 2 mm long.
The achenes of burdock are obovate or obliquely obovate, 5-7 mm long and 2-3 mm wide, compressed on both sides, light brown, with many fine vein lines and dark brown color spots or without color spots. The pappus is in many layers, light brown; the pappus bristles are scabrous, unequal in length, up to 3.8 mm long, not fused into a ring at the base, and fall off separately. The flowering and fruiting period is June to September.
Burdock contains inulin, cellulose, protein, calcium, phosphorus, iron, and various vitamins and minerals needed by the human body. Among them, the carotene content is 150 times higher than that of carrots, and the contents of protein and calcium rank first among root and stem vegetables. Burdock root contains inulin and volatile oil, arctic acid, various polyphenolic substances and aldehydes, and is rich in cellulose and amino acids.
Burdock root contains various amino acids essential to the human body, and their content is relatively high, especially the content of amino acids with special pharmacological effects. For example, aspartic acid, which has a brain-strengthening effect, accounts for 25-28% of total amino acids, and arginine accounts for 18-20%. It also contains major and trace elements essential to the human body such as Ca, Mg, Fe, Mn, and Zn.