what is perianth in flower

The perianth is the non-reproductive part of a flower that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepals when called a perigone. The term perianth is derived from Greek περί (peri, "around") and άνθος (anthos, "flower") . The perianth is a non-essential organ of the flower that protects the inner essential organs and helps indirectly in reproduction. The sepals and petals are accessory parts or sterile appendages that protect the flower buds and attract pollinators, but they are not directly involved with sexual reproduction. The perianth may be described as being either dichlamydeous/heterochlamydeous in which the calyx and corolla are clearly separate, or homochlamydeous, in which they are indistinguishable (and the sepals and petals are collectively referred to as tepals) .