Capsella bursa-pastoris, commonly known as shepherd's purse or lady's purse, is a small flowering plant in the mustard family. It has been described as a protocarnivore because its seeds contain mucilage, which traps nematodes.

The plant is native to Eurasia but is naturalized and considered a common weed in many parts of the world, especially in colder climates. It has a number of culinary uses.