Bidens bipinnata is commonly known as Spanish needles, devil's needles or butterfly needles. These synonyms refer to the plant's distinctive seed heads, which are shaped like tiny darts and can easily attach themselves to clothing or fur. Other synonyms for Bidens bipinnata include beggarticks, tickseed sunflower, and two-leaved beggarticks. The plant is an annual herb that grows up to 6 feet tall, and its bright yellow flowers bloom from late summer to early fall. It is found throughout North America in fields, along roadsides, and other open areas. Despite being a weed, Bidens bipinnata is known for its medicinal properties, including its ability to treat fevers and reduce inflammation.