"X" is the outermost whorl of the flower and contains "Y". Y is green, leaf like and protect the other whorls of the flower.
Identify X and Y.

Calyx of the flower contains sepals which are green in colour and look like leaf and protect the other whorls of the flower. Corolla is present inside the calyx and made up of petals. Petals are different in color and shapes and protects the other whorls present inside it. It attracts insects for pollination due to its color. Androecium is present inside the corolla and made up of stamens. Each stamen contains filament, anther and a connective.