Plants 1-2 m tall, branched. Stem fistular. Leaves 2-3-pinnate; leaflets lanceolate to oval, 3-5 cm long, 3 mm to 1 cm broad; margin serrate. Involucral bracts lacking. Rays c. 15, 4-6 cm long. Involucel of linear bractlets. Fruit ovoid, 2-3 mm long; ridges corky. Inner seed face slightly concave.