During cross pollination, pollen grains must travel via vectors from the male anther of one plant to the female stigma of another plant of the same species.
Pollination is the first step in the sexual reproduction of flowering plants. There are two types of pollination, each being categorized by the link between where the pollen is originating from and where pollen placement occurs.
The level of success in achieving sexual reproduction for cross pollinated species heavily depends on how efficient the pollinating vectors are. This is an important fact to remember as the pollen MUST be transferred from one plant to another for seed set to occur. Of course, seed set is the beginning of the next generation and this is why conserving our native biotic pollinators is so important. These type of cross pollinated plants would simply not be able to reproduce without them!