dahlia
- Related Topics:
- Asteraceae
- Dahlia variabilis
- Dahlia coccinea
- garden dahlia
dahlia, (genus Dahlia), genus of about 40 species of flowering plants in the aster family, renown for their attractive flowers. About six of the species in the Dahlia genus have been bred for cultivation as ornamental flowers and are popular in the floral industry and in gardens. The thousands of dahlia cultivars are classed into a variety of types, including single, double, pompon, cactus, waterlily, peony-flowered, and dinnerplate dahlias. Dahlias grow well in most garden soils. They begin flowering late in the summer and continue flowering until interrupted by frost in the autumn.
- Kingdom: Plantae
- Division: Angiosperm
- Order: Asterales
- Family: Asteraceae
- Genus: Dahlia
See also list of plants in the family Asteraceae.
Physical description
Dahlias are tuberous perennials, and most have simple leaves that are segmented and toothed or cut. The composite flower heads may be white, yellow, red, or purple in color. Wild species of dahlias have both disk and ray flowers in the flowering heads, but many varieties of ornamentals such as the common garden dahlia (D. pinnata) have shortened ray flowers.
History and cultivation
Dahlias are native to the higher elevations of Mexico and Central America, and made their way to Europe with Spanish colonization of the region. The dahlia was first introduced into Great Britain from Spain in 1798. Many of the countless varieties of dahlias, including double-flowered forms, were subsequently developed in Britain and elsewhere from the species D. variabilis and D. coccinea.
