Pollen grains are so tiny that we can hardly see them with the unaided eye;
however, they become apparent under a microscope.

In fact, a viewer can see that both the size and the shape are unique to each particular species.

Since pollen is resistent to decay , it is significant that scientists often study the unique " fingerprint " of the pollen grains they unearth..
They can therby identify plants that people cultivated centuries ago.

Importantly , the distinct characteristics of each type of pollen enable
flowers to recognize the pollen of their own species...