Answer:
Petals and sepals are collectively referred to as the Perianth .
Explanation :
The perianth consist of petals and sepals. It a non-reproductive part of a flower but it is a vegetative organ. It is just the protective covering of the sexual organs of the flower.
There major function is to attract the pollinators for pollination. They are of four different types. They are always bright coloured and are beautifully designed. Petals and sepals are part of a sterile appendages. Being a part of a flower ,the petals and sepals do not take part in the process of sexual reproduction.