Dahlia is a genus of bushy, tuberous, herbaceous perennial
plants native to Mexico. A member of the Asteraceae, dicotyledonous plants, related species include the sunflower, daisy, chrysanthemum, and zinnia. The tubers were grown as a food crop by the
Aztecs, but this use largely died out after the Spanish Conquest. Attempts to
introduce the tubers as a food crop in Europe were unsuccessful. Source
