A sepal is a part of a flower that typically protects the developing bud. It is usually green and leaf-like, forming the outermost whorl of the flower. Sepals can vary in size, shape, and color, depending on the species of the plant. They play a crucial role in supporting the petals and can help attract pollinators. In many flowering plants, the collective group of sepals is called the calyx. Sepals can also serve to shield the flower from harsh environmental conditions, such as extreme temperatures or heavy rain. Understanding sepals is essential for studying plant anatomy and reproduction.