A calyx is the outermost part of a flower, typically consisting of green leaf-like structures called sepals. Its primary function is to protect the developing flower bud before it opens. The calyx can also help support the flower once it blooms, contributing to the overall structure of the flower. In many flowering plants, the calyx is often found beneath the petals and can vary in shape, size, and color. It plays a crucial role in the reproductive process by safeguarding the more delicate parts of the flower, such as the petals, stamens, and pistils.