Bidens wiebkei, a member of the Asteraceae (sunflower) family, is a perennial herb 0.5 to 1 m (1.6 to 3.3 ft) tall and woody at the base. The opposite, pinnately compound leaves are 7 to 13 cm (2.8 to 5.1 in) long and each has three to seven leaflets, 2.5 to 8 cm (1 to 3 in) long and 1 to 2.5 cm (0.4 to 1 in) wide. Flower heads are arranged on side branches in clusters of usually 10 to 30, each1.6 to 2.5 cm (0.6 to 1 in) in diameter and comprising 4 to 6 sterile, yellow ray florets, about 10 to 12 mm (0.5 in) long and 2 to 5 mm (0.08 to 0.2 in) wide, and 9 to 18 bisexual, yellow disk florets. Fruits are brownish-black achenes (dry, one-seeded fruits), which are curved or twisted and winged and measure 6 to 9 mm (0.2 to 0.4 in) long and 0.9 to 2 mm (0.04 to 0.08 in) wide.