The bright, late-season flowers commonly known as “mums” are a staple of autumn decoration, providing a burst of color when most other garden plants fade. The name is a popular abbreviation for Chrysanthemum, a genus of flowering plants celebrated for its vast diversity in bloom color and form. These highly cultivated flowers are particularly valued because they naturally bloom in the fall, making them a symbol of the changing season. Understanding what kind of flower a mum is requires appreciating both its ancient botanical roots and the extensive modern breeding that has created thousands of distinct varieties.
The Botanical Identity of Chrysanthemums
Mums belong to the genus Chrysanthemum, a member of the large Asteraceae family, often called the daisy or aster family. This family is characterized by composite flower heads, meaning what appears to be a single flower is actually a dense cluster of many tiny individual flowers, or florets. The center is composed of disk florets, which are surrounded by the petal-like ray florets.
The genus is native primarily to East Asia, with China being the center of its diversity. Chrysanthemums have been cultivated there for over 1,500 years, initially for medicinal use and later for ornamental beauty. Modern cultivated mums are largely derived from Chrysanthemum × morifolium, a complex hybrid resulting from centuries of cross-breeding that has led to thousands of unique cultivars.
Understanding the Many Bloom Forms
The most striking feature of chrysanthemums is the incredible variation in their flower structure, which horticulturalists classify into 13 distinct bloom classes. These classifications are based on the arrangement, length, and shape of the ray and disk florets.
Incurved types, some of the largest blooms, have ray florets that curve smoothly inward, creating a spherical shape. The Reflexed type has florets that curve downward and outward, often overlapping to give the bloom a flattened globe shape. The Pompon class features small, dense, and fully rounded blooms, ranging from tiny button sizes to spheres nearly four inches across.
Other classifications include the Spider type, recognizable by its long, thin, tubular ray florets that may coil or hook at the ends. The Spoon type features tubular ray florets with a flattened, spoon-like tip. Single and Semi-Double forms are the simplest, resembling classic daisies with one or two rows of ray florets surrounding a prominent central disk.
Mums for the Garden Versus Mums for the Florist
Commercial chrysanthemums are grouped into two major categories based on their intended use and ability to withstand cold temperatures: garden mums and florist mums. Garden mums, also known as hardy mums, are perennial varieties bred to survive the winter and return for multiple years in many growing zones. These plants typically have a mounding, bushy growth habit and smaller, more numerous flowers.
Florist mums are often less winter-hardy and are treated as seasonal annuals or used as cut flowers. These varieties are frequently bred for large, showy blooms on single stems, making them ideal for floral arrangements or temporary potted displays.
Both types are known for their spectacular fall bloom, which is regulated by photoperiodism. This means the plants initiate flower buds only when daylight hours shorten, signaling the arrival of autumn. Growers manipulate light exposure in greenhouses to force these plants to bloom precisely when they are most in demand for fall decorating.