鬼针草（学名：Bidens pilosa），一年生草本植物。分布非常广泛，中国大部分地区有分布。全草可作为中药使用。

鬼针草一名始见于《本草拾遗》，异名有鬼钗草（《本草拾遗》）、三叶鬼针、三叶鬼针草、鬼黄花、山东老鸦草、婆婆针、鬼骨针、叉婆子、鬼蒺藜、粘身草、钢叉针等。

Bidens pilosa is a species of flowering plant in the aster family. It is native to the Americas but it is known widely as an introduced species of other regions, including Eurasia, Africa, Australia, and the Pacific Islands. It is a tall branched weed with thin yellow flowers that develop into a cluster of barbed seeds. Its many common names include black-jack, beggar-ticks, cobbler's pegs, and Spanish needle. The seeds are like short, stiff hairs. They get stuck in feathers, fur, or socks, etc. This bur is widespread throughout the warmer regions of the world. Its little black seeds hook onto clothes or horses and thereby the bur spreads itself around. It is susceptible to hand weeding if small enough, even then must be bagged, and thick mulches may prevent it from growing. Each seed has two to four barbed spines. A weed of gardens, woodlands, and waste areas, a person who brushes against it will end up covered in the burs and need to pick them off one by one. Although this plant is considered a weed in some parts of the world, in other parts it is a source of food or medicine. For example, it is reportedly widely eaten in Africa.