The leaves of black purple sunflower are opposite, sometimes the upper part or all of them are mutual. Its leaves have petioles, usually three veins after leaving the base.
The flowers of black purple sunflower are head like inflorescences, which are solitary or arranged in the shape of an umbrella. There are many small flowers with different shapes in the inflorescence, a layer of asexual tongue shaped flowers on the periphery, and most of the hermaphroditic flowers that can bear fruit in the center. The flower of ligulate flower is unfolded and yellow in color; the tube part of tubular flower is very short, the upper part is bell shaped, the upper part is yellow, purple or brown, with 5 lobes.
Achenes oblong or obovoid, slightly flattened or with 4 thick ribs.
