Bidens micrantha subsp. ctenophylla is an erect perennial herb, 0.5 to 1.5 m (1.6 to 5 ft) tall, and slightly woody at the base. The leaves are simple or occasionally trifoliate (a compound leaf with three leaflets), 6 to 9 cm (2.4 to 7.5 in) long with one to nine leaflets that are egg- and lanced-shaped, 3.5 to 13.5 cm (1.4 to 5.3 in) long, 0.5 to 6 cm (0.2 to 2.2 in) wide. The leaves are not ciliate (haired) on margins. Flower heads are small compound cymes, with five to nine rays per head that are 7 to 16 mm (0.3 to 0.6 in) long. The rays and corollas are yellow. The achenes are black, straight, awned, rarely winged, 5 to 14 mm (0.2 to 0.6 in) long, 0.7 to 1.5 mm (0.03 to 0.06 in) wide, and without hairs.