The female of the species.

I failed Biology. So it has been of interest for Danny Liv and myself to figure out how hazel trees produce hazel nuts (i.e. seeds) that could become young trees.

 

The basic answer is in this photo. Many of us are familiar with yellow catkins, seen here on the left of the photo and also in the background. These are male catkins that produce a heck of a lot of pollen. Try standing underneath and shaking the catkin and you'll see it on your clothes. That pollen is blown by the wind and with luck will find a female, seen here to the mid-right of the photo as a tiny, really tiny red flower. As I understand it, but don't forget I failed Biology, that pollination has to come from a different hazel tree. In other words, it is not as simple as transferring pollen from male to female as shown in this photo! Once that has happened, a nut / seed will develop. Then come autumn, perhaps a squirrel will take a nut and "squirrel it away" in the ground from which potentially a young sapling might grow,

Done