About Bidens laevis (L.) Britton, Sterns & Poggenb.
Bidens laevis (L.) Britton, Sterns & Poggenb. is a species of flowering plant in the daisy family, commonly known as larger bur-marigold and smooth beggarticks. It is native to South America, Mexico, and the southern and eastern United States. It grows in wetland habitats, including estuaries and riverbanks. Bidens laevis resembles its relative Bidens cernua in appearance, and the two species are sometimes confused with one another.
This plant is an annual or perennial herb that grows over 20 centimeters tall, and can grow much taller. It often exceeds one meter in height, and sometimes approaches two meters. Its leaves are narrow and lance-shaped, 5 to 15 centimeters long, with finely toothed edges and pointed tips. The inflorescence produces one or more flower heads, which bend downward as they become heavy with fruit after flowering. Each flower head has a center made up of yellow disc florets, surrounded by a fringe of 7 or 8 yellow ray florets that each grow up to 3 centimeters long. Its fruit is a dry achene with sharp barbs that stick to fur and clothing, an adaptation that helps the plant disperse its seeds.
