Calyx

The calyx is the outermost whorl of the flower, and its individual members are called sepals. The sepals are generally green and leaf-like, and their main role is to enclose and protect the other, more delicate floral parts while the flower is still a developing bud.

The calyx can take two forms depending on whether its sepals are joined:

• Gamosepalous — the sepals are united (fused) together, at least at the base.
• Polysepalous — the sepals are free from one another. …