Arctium lappa, commonly called greater burdock, edible burdock, lappa, or beggar's buttons, is a biennial plant of the Arctium (burdock) genus in the Asteraceae family, cultivated in gardens for its root used as a vegetable. It is an invasive weed of high-nitrogen soils.

Ferredoxin from Arctiumlappa consists of a single polypeptide chain of 97 residues, four of which are cysteine. A novel lignan, diarctigenin, together with the known butyrolactone derivatives, arctigenin and arctiin, has been isolated from the seeds of Arctiumlappa. Its structure was elucidated as bis-5′,5′-arctigenin by spectral analyses and chemical modification.

The flowers are purple and grouped in globular capitula, united in clusters. They appear in mid-summer, from July to September. Near villages, roadsides, near rivers, wet and waste places, forest margins, thickets, valleys, slopes; 700-3500 m. Throughout China except for Hainan, Taiwan, and Xizang [Afghanistan, Bhutan, India, Japan, Nepal, Pakistan; SW Asia, Europe].