A bract is a modified leaf, usually small, found beneath a flower or inflorescence (a group of flowers). While often overlooked, bracts play a significant role in plant structure and can sometimes be mistaken for petals.
Understanding Bracts: A Closer Look
- Definition: A bract is a leaf-like structure that is modified in form and function. It is typically positioned below a flower or flower cluster.
- Function: Bracts can serve various purposes, including protecting the developing flower or inflorescence, attracting pollinators (as in the case of poinsettias where the colorful bracts are mistaken for petals), or aiding in seed dispersal.
- Appearance: Bracts vary greatly in size, shape, and color. They can be small and inconspicuous or large and showy, even resembling petals as seen in poinsettias and dogwoods. The bracts of artichokes are a particularly notable example of substantial and modified leaves.
- Examples:
- Poinsettia: The vibrant red, white, or pink parts of a poinsettia that we often consider "flowers" are actually bracts. The true flowers are small and yellow, found in the center of the bracts.
- Dogwood: Similar to poinsettias, dogwoods feature showy white or pink bracts surrounding small, inconspicuous flowers.
- Artichokes: The fleshy, edible parts of an artichoke are bracts that protect the developing flower buds.
- Sedges: In sedges, the term "bract" has a more specific meaning, usually referring to the bract(s) directly beneath the inflorescence on the culm (main stem).
Bracts vs. Petals: Key Differences
It's important to distinguish bracts from petals. Petals are modified leaves that make up the corolla, the inner whorl of a flower. Bracts are positioned below the flower or inflorescence, while petals are part of the flower. However, as demonstrated by examples like poinsettias and dogwoods, the line between bract and petal can be blurry, with bracts sometimes evolving to take on the role of attracting pollinators.
