Kronblätter

Kronblätter are the petals of a flower, the sterile organs that typically form the corolla and are visible inside the calyx. The term comes from German botany, where Kronblätter describe the colorful, leaf-like structures that often attract pollinators. In English, they are commonly referred to as petals or, collectively, as the corolla.

Structure and variation: Petals may be free or fused to form a corolla tube, a funnel shape, or a wheel-like ring. They can be arranged in a spiral or in distinct whorls around the center of the flower. Kronblätter can exhibit actinomorphic symmetry (radial) or zygomorphic symmetry (bilateral). Their number, shape, and size vary widely among plants, contributing to the diversity of flower forms.

Function: The primary role of Kronblätter is ecological: their color, patterns, and scent attract pollinators and help guide them to nectar and pollen. Petals may also play a protective role for reproductive structures and, through color contrasts and nectar guides, influence pollination efficiency.

Variation across plant groups: In some families, petals are highly conspicuous and large (as in roses and lilies). In others, such as many members of the Asteraceae, what appears to be petals may be modified structures, with ray florets surrounding centralized disk florets. In Fabaceae, petal arrangement is often described in terms of standard, wings, and keel.

Taxonomy and terminology: Kronblätter is the German term for petals within the broader concept of the perianth, which also includes sepals (Kronblätter der Kelchblätter) and the corolla as a whole. Understanding Kronblätter is fundamental to flower morphology and pollination biology.