Identify the part of the pistil which traps and holds the pollen.

The pistil is the female reproductive organ in a flower. It consists of the stigma (the receptive part), style (a stalk connecting the stigma to the ovary), and the ovary (which contains the ovules, or potential seeds). 

The stigma is the sticky, receptive part of the pistil where pollen grains germinate. The stigma traps the pollen coming from the anther during pollination and allows the pollen tube to grow down the style to reach the ovules in the ovary. Once the pollen reaches the ovules, it can fertilize them and result in the production of seeds. The stigma plays a crucial role in the reproduction of the plant and ensures the continuation of the species.