Bidens alba

Bidens alba is a species of flowering plant in the family Asteraceae, commonly known as shepherd's needles, beggarticks, Spanish needles, or butterfly needles. Bidens means two- toothed, describing the two projections found at the top of the seeds, and alba refers to the white ray florets. This plant is found in tropical and subtropical regions of North America, Asia, South America, and Africa, situated in gardens, road sides, farm fields and disturbed sites. B. alba is an annual or short-lived perennial, which is considered a weed in the United States. However, B. alba leaves are edible and can be used as medicinal remedies....read more on Wikipedia.