Achyranthes aspera (common name: prickly chaff flower,devil's horsewhip, Sanskrit: अपामार्ग apamarga) is a species of plant in the Amaranthaceae family. It is distributed throughout the tropical world. It can be found in many places growing as an introduced species and a common weed. It is an invasive species in some areas, including many Pacific Islands environments.
Slender erect perennial, sometimes climbing or scrambling. The leaves are often covered in silvery indumentum when young (less noticeable in shade growing specimens) Inflorescences dense at first but elongating up to 25 cm with more widely spaced flowers. Flowers greenish to silvey-white, often tinged with purple-red.