As a member of the Asteraceae or aster/sunflower family, the dahlia has close relatives like the chrysanthemum, daisy, dandelion, marigold and zinnia. Dahlia varieties increased from about 100 in 1820, to over 2,000 by 1840. In 1872, a spectacular and unusual red dahlia (Dahlia juarezii) bloomed from a box of tubers sent from Mexico to Holland. It reawakened interest in dahlias, and what they mean, literally, figuratively and symbolically.
The dahlia originated in Mexico, where a group of Spanish adventurers discovered it in the 16th century. The common name “dahlia” derives from the surname of the Swedish botanist, Andreas/Anders Dahl (1751 to 1789). In 1789, the Spanish botanist, Abbe Cavanilles, who became director of the Royal Gardens in Madrid, created this name after receiving dahlia seeds. "Valley flower" is another name for the dahlia because "dahl" means "valley." Dahlia is also the genus name of this beautiful flower. There are over 20 known Dahlia species and thousands of hybrids developed from them. The most common hybrids are a cross between Dahlia pinnata and Dahlia coccinea, two of the earliest named species.
The dahlia flower definitely stands for diversity. It has eight genes compared to two for most other flowers. For this reason, the dahlia can be called the Houdini of the garden, because it takes a myriad of shapes, colors and sizes. Some of its admirers refer to the dahlia as the “queen of the autumn garden” to reflect the height of its blooming season which extends from mid-summer through early frost. Dahlias appear in a wide spectrum of colors, some as large as 12 inches across, and over 20 feet tall for wild species.
The figurative term “blue dahlia” points to the fact that no blue variety of the flower exists to date. The term suggests something that is unattainable. A prize of 1,000 British pounds sterling remains on offer to anyone who cultivates a blue dahlia. This prize offer dates back to 1826, perhaps an indication of the degree of difficulty in completing this cultivation challenge.
Symbolically, the dahlia denotes elegance and dignity. It also signifies a warning, change, travel or betrayal, according to the Whats-Your-Sign website.
Literary, Literal Significance
An Aztec herbal, the “Codex Barberini,” dating from 1552, documents the medicinal uses of the dahlia in the treatment of epilepsy. The Aztec name for dahlias was “acocoxóchitl” which means “plant with tube-like stems.” This description refers to its literal use, as the Aztecs carried water in the hollow stems of a tall variety now called Dahlia imperialis.
The dahlia became the official flower of the City of San Francisco, California, in 1926. The dahlia is also the national flower of Mexico. President Adolfo López Mateos officially adopted the dahlia as the country’s floral emblem in 1963.