“THE PISTILS OF A FLOWER are considered to be composed of carpels. A carpel is a theoretical construct interpreted as modified leaves bearing structures called ovules, inside which the egg cells ultimately form. A pistil may consist of one carpel, with its ovary, style and stigma, or several carpels may be joined together with a single ovary, the whole unit called a pistil.”
https://en.m.wikipedia.org/wiki/Gynoecium