A dahlia is a garden flower known for its spectacular blooms and incredible variety. Dahlias come in nearly every color except blue, and their petals can arrange themselves in dozens of different patterns: some look like perfect spheres made of tightly packed petals, others have spiky petals pointing in all directions like fireworks frozen in time, and still others resemble water lilies or pom-poms.

These flowers grow from underground tubers (thick roots that store energy, like potatoes) and can range from tiny blooms the size of a golf ball to dinner-plate-sized flowers nearly a foot across. Gardeners prize dahlias because they bloom from midsummer until the first frost, providing color when many other flowers have finished for the season.

Dahlias originally grew wild in the mountains of Mexico and Central America. The Aztecs cultivated them long before Europeans arrived, using the tubers as a food source and the hollow stems as water pipes. Spanish explorers brought dahlias to Europe in the late 1700s, where enthusiasts began breeding them into the thousands of varieties we see today.