Cosmos are herbaceous perennial plants growing 0.3–2 m (10 in–6 ft 7 in) tall. The leaves are simple, pinnate, or bipinnate, and arranged in opposite pairs. The flowers are produced in a capitulum with a ring of broad ray florets and a center of disc florets; flower color is very variable between the different species. The genus includes several ornamental plants popular in gardens. Numerous h.