Dahlia is a genus of bushy, summer and autumn flowering, tuberous perennials. They are originally from Mexico and also the national flower of that country.

In 1872 a box of Dahlia roots were sent from Mexico to the Netherlands. Only one plant survived the trip, but produced spectacular red flowers with pointed petals. Nurserymen bred from this plant, which was named Dahlia juarezii with parents of Dahlias discovered earlier and these are the progenitors of all modern Dahlia hybrids. Ever since, plant breeders have been actively breeding Dahlias to produce hundreds of cultivars, usually chosen for their stunning and brightly colored flowers.

The dahlia is named after Swedish 18th-century botanist Anders Dahl.