The common carrot (Daucus carota) is a biennial species, typically dedicating its first year to growing the edible root. In its second year, the plant produces a tall stalk topped by a distinctive flower, a process called “bolting.” This occurs after the plant has stored enough energy to reproduce. The resulting flower structure is intricate, presenting a lacy, flat-topped display.
The Signature Structure of the Flower Head
The carrot flower head is a large, intricate floral arrangement called a compound umbel. This structure consists of smaller, secondary flower clusters, known as umbellets, all originating from a single point atop the main stem. When fully open, the inflorescence is flat-topped or slightly dome-shaped, resembling fine lace and often reaching 3 to 6 inches across.
Beneath the main umbel, the plant features a whorl of specialized, finely divided leaves called bracts. These bracts, which are often three-forked or pinnate, serve as a unique identifying trait for Daucus carota. The compound umbel is composed of many individual umbellets, ranging from twenty to ninety per head, each containing numerous tiny flowers.
Detailed Appearance of Individual Florets
The individual flowers, or florets, that make up the umbel are small, measuring only about 2 to 3 millimeters across. Each tiny floret is usually dull white or creamy white, featuring five small petals that often curve slightly inward at the tips. The flowers are packed tightly together on slender stalks, contributing to the overall lacy texture of the flower head.
A prominent feature, especially in the wild variant, is a single, dark-colored floret located directly in the center of the main umbel. This central floret is typically a deep purple, reddish, or pink hue, providing a stark visual contrast against the surrounding white flowers. Studies suggest this dark spot may act as a form of insect mimicry, either attracting certain pollinators like beetles or deterring parasitic insects.
Differences Between Wild and Cultivated Varieties
The wild carrot, known as Queen Anne’s Lace, and the cultivated garden carrot belong to the same species, Daucus carota, but are different subspecies. Both share the fundamental structure of the compound umbel. Wild variants tend to have a consistent presence of the distinctive central dark floret in their umbels.
Cultivated carrot varieties, bred for large edible roots, may produce larger and denser flower heads if allowed to bolt. However, the prominent dark purple or red central floret seen in the wild type is often less common or completely absent in cultivated garden carrots. The wild version also has seeds with appendages, which the cultivated variety lacks.
Transformation into the Seed Head
After successful pollination, the umbel transforms as the seeds begin to mature. The initially flat or slightly convex flower head contracts, with the outer rays curling inward toward the center. This inward movement creates a tight, concave, cup-like shape.
This post-flowering stage is often described as resembling a bird’s nest due to its curled, compact shape. The contracting structure serves to protect the developing seeds, which are small, dry, and covered in tiny hooked spines.