"cosmos atrosanguineus" is a herbaceous perennial plant growing to 40–60 cm tall, with a fleshy tuberous root. the leaves are 7–15 cm long, pinnate, with leaflets 2–5 cm long. the flowers are produced in a capitulum 3-4.5 cm diameter, dark red to maroon-dark brown, with a ring of six to ten (usually eight) broad ray florets and a center of disc florets; they have a light vanillin fragrance (like many chocolates), which becomes more noticeable towards the end of the day.