any of several plants of or developed from the species Dahlia pinnata having tuberous roots and showy rayed variously colored flower heads; native to the mountains of Mexico and Central America and Colombia
A dahlia is a garden flower with a lot of brightly coloured petals. a large garden flower with a bright colour (Anders Dahl (1751-89), Swedish plant scientist). Any of the 12-20 species of tuberous-rooted herbaceous plants that make up the genus Dahlia, in the composite family, native to higher elevations of Mexico and Central America. The leaves of most are segmented and toothed or cut. About six species have been bred for cultivation as ornamental flowers. Wild species have both disk and ray flowers in the flowering heads, but many varieties of ornamentals, such as the common garden dahlia (D. bipinnata), have shortened ray flowers. Dahlia flowers may be white, yellow, red, or purple