Plants 1-3 m tall, glabrous. Leaves petiolate, bipinnate; segments oval, deeply serrate. Involucre of 5-8 minute, linear to oval bracts. Rays 8-20, unequal, glabrous. Involucel of 3-5, 1-2 mm long, linear to ovate bractlets. Pedicels 2-3 times longer than the flowers. Fruit broadly ovoid, 2-3 mm long, 2-2.5 mm broad; ridges prominent, obtuse, undulate; styles reflexed; vittae numerous, minute.