Bidens pilosa, commonly known as Black-Jack, Beggarticks, Spanish Needle, or Cobbler’s Pegs, is an annual herb that is native to tropical and subtropical regions of the Americas, including the southern United States. It thrives in a variety of disturbed habitats such as roadsides, cultivated fields, and gardens. Typically, it grows up to 6 feet tall and has a branching habit. The plant produces flowers mainly in summer and autumn, featuring white ray florets surrounding yellow disc florets. These flowers are modest in appearance but can be quite numerous, leading to prolific seed production. The barbed fruits are designed to catch onto the fur of animals or clothing of humans, facilitating long-distance dispersal.

Bidens pilosa is known for its rapid growth and ability to colonize disturbed areas quickly, making it a useful plant for soil stabilization. However, its invasive nature can be problematic, and it is considered a weed in many regions. It requires full sun to partial shade, moderate water, and is not particular about soil type, though it prefers well-drained soils. In cultivation, it is rarely used due to its invasive potential and is more often managed as a weed. Gardeners should be cautious about introducing it to new areas, as it can outcompete native flora and become a nuisance.CC BY-SA 4.0