Bidens micrantha ssp. kalealaha, of the Asteraceae (sunflower) family, is an erect perennial herb, slightly woody at the base, and 0.5 to 1.5 m (1.6 to 4.9 ft) tall. Leaves are 6 to 19 cm (2.4 to 7.5 in) long with three to seven and sometimes up to nine lance-shaped leaflets, each 2.5 to 10 cm (1 to 4 in) long and 0.5 to 3 cm (0.2 to 1.2 in) wide. Flower heads are arranged at the top of the plant and on side branches in open clusters of 15 to 50. Each flower head is 2.5 to 4.5 cm (1 to 1.8 in) in diameter and comprises 5 sterile, yellow ray florets 15 to 27 mm (0.6 to 1.1 in) long and 5 to 7 mm (0.2 to 0.3 in) wide, and 9 to 15 disk florets in the center of the head. Fruits are black achenes, 8 to 14 mm (0.3 to 0.6 in) long and 0.8 to 1.5 mm (0.03 to 0.06 in) wide, with two awns and no wings.