Perianth

The perianth is the non-reproductive outer part of a flower, made up of the calyx (sepals) and corolla (petals) together. When the sepals and petals cannot be told apart — as in many lilies and their relatives — all the segments are called tepals and the whole whorl is simply the perianth. In some plants the perianth segments are fused into a tube or cup rather than being free.