The common daisy, typically Bellis perennis, is not a chrysanthemum, which belongs to the genus Chrysanthemum. Although these two flowers share a strikingly similar appearance, featuring a central disk surrounded by radiating “petals,” they are scientifically classified as separate plants. The strong visual resemblance often causes confusion; one type of chrysanthemum is commonly referred to as a “daisy mum.” Their separation is defined by unique genetic structures and resulting differences in physical characteristics and life cycles.
The Shared Family Tree
Daisies and chrysanthemums look similar because they both belong to the same large biological group, the family Asteraceae. This family, often called the daisy or sunflower family, is one of the largest plant families in the world. The defining characteristic of the family is the composite flower head, which is a dense cluster of many tiny individual flowers called florets.
The familiar “petals” on the outside are technically called ray florets, while the central button is composed of densely packed disk florets. These small individual flowers are all attached to a common base, or receptacle. This composite structure unifies a vast array of plants, including sunflowers, dandelions, and asters, under the Asteraceae umbrella.
Distinct Biological Identities
While they share the Asteraceae family, the scientific distinction lies at the genus level, which is a much more specific category. The common lawn daisy (Bellis perennis) is placed within the genus Bellis. Chrysanthemums, conversely, belong to the genus Chrysanthemum, which includes species like Chrysanthemum morifolium, the popular garden mum.
This separation means their genetic blueprints, evolutionary histories, and native origins are fundamentally different. The common daisy is native to Europe and temperate Asia, whereas most garden chrysanthemums trace their ancestry back to East Asia, particularly China.
The genus-level difference also dictates the finer points of their floral anatomy, such as the number and arrangement of chromosomes, which do not permit them to naturally interbreed. Bellis typically produces a simple, solitary flower head on a leafless stalk, while Chrysanthemum species exhibit a much more complex branching structure.
Key Differences in Growth and Appearance
The most noticeable difference between the common daisy and a typical garden chrysanthemum is their overall size and growth habit.
Size and Habit
Bellis perennis is a low-growing, compact plant, rarely exceeding 8 inches in height. Its leaves form a rosette close to the ground. Chrysanthemums are generally much taller and bushier, often reaching heights of one to three feet with complex, multi-branched stems.
Leaf Structure
The leaves also offer a clear distinction, even when the plants are not flowering. The common daisy has small, rounded or spoon-shaped leaves that are simple and often slightly hairy. Chrysanthemum leaves are deeply lobed or serrated, giving them a more jagged appearance, and are aromatic when crushed.
Bloom Time and Form
Their bloom times are another way to tell them apart, especially in temperate regions. Bellis perennis flowers for a long season, often from early spring through the summer. Garden chrysanthemums are primarily short-day plants, known for their late-season display. They typically burst into color in late summer and continue through the fall. The chrysanthemum also offers a wider variety of flower forms, ranging from simple single flowers to complex, double-petaled blooms not seen in the common daisy.