Capsella bursapastoris

Capsella bursa-pastoris, known as shepherd's purse or lady's purse because of its triangular flat fruits, which are purse-like, is a small annual and ruderal flowering plant in the mustard family (Brassicaceae). Scientists have referred to this species as a protocarnivore, since it has been found that its seeds attract and kill nematodes as a means to locally enrich the soil. It 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....read more on Wikipedia.