The knob at the top is called the stigma. Pollen sticks to the stigma. The elongated thin part is called the style. The enlarged part at the bottom is called the ovary. Since all three parts of the pistil are clearly visible when the stamens are removed, this flower is hypogynous.
Some flowers are radially symmetrical like the lily flower above.
The green sepals are fused at the base. The petals are fused into a single structure. The style and stigma have been left intact, and the ovary has been sliced longitudinally. Since the style, stigma and ovary are visible. This, too, is a hypogynous flower.