scarlet spiderling

This plant grows in a wide variety of habitats, including disturbed areas as a common roadside weed. It is a low-lying, sprawling perennial herb producing reaching stems which can exceed a meter in length. The stems are somewhat hairy and sticky with glands. The generally oval-shaped leaves are held on short petioles. They are wavy along the edges and may have reddish margins. The inflorescence is a small head of tiny frilly flowers, each just a few millimeters long. The flowers are often bright scarlet to red-violet in color but can be shades of pink, yellow, or white.

The native range of the species is uncertain. It is considered to be native to the Americas, Africa, the Arabian Peninsula, the Indian sub-continent and parts of Australia. Some data suggests the species originated in an area between the southern USA and northern South America and introduced to other parts of the world by human activity. The species' range in Australia has expanded under human activity. In Africa, B. coccinea has been found in Uganda, Kenya, and Tanzania. The uncertainty concerning the native range is exacerbated by the difficulty of distinguishing species within the B. diffusa-B. coccinea complex.

The plant has historically been used for its medicinal properties. The leaves and roots of B. coccinea are used medicinally in countries including Cameroon, Ethiopia, Namibia, Nigeria, Tanzania, Mexico, Brazil, Argentina, and Paraguay. In traditional Mexican Medicine, B. coccinea has been used to treat conditions such as diarrhea and dysentery. The plant is usually used medicinally to treat pain and inflammation because of its anti-inflammatory and antinociceptive properties. The chemical explanation for these properties is an active topic of research. It is also eaten by humans and used as animal feed. A flour can be made from its seeds.