Now, pollen from plants, which are wind dispersed like trees and grasses and so on tend to cause the most hay fever.

And it isn't just bright flowers that have pollen it's also trees and grasses.

Pollen is produced by the anthers of flowers.

The fossilized pollen was not of savanna vegetation.

What the honey bee does it pollinates, takes nectar from the flower, pollinates another flower, cross pollinates.

Each anther can carry up to 100,000 grains of pollen, so, it's quite prolific stuff.

They get paid by pollen and nectar, to move that male sperm, the pollen, from flower to flower.

A different pollen signature, if you like, or a different pollen fingerprint.

very small pink roses.

I am allergic to pollen.

Most pollen that causes hay fever for us is from plants that use the wind to disseminate the pollen, and that's a very inefficient process, which is why it gets up our noses so much.

That's a geranium pollen.

Cool pollen, though.

So all the grasses, which means all of the cereal crops, and most of the trees have wind borne pollen.

This is the Monterey Pine, which has little air sacks to make the pollen carry even further.

The insects and other species can take the pollen, transfer it directly to where it's required.

My nose! My hay fever!

Pollen is a flower's way of making more flowers.

That little hole in the middle there is for the pollen tube, and when the pollen finds its special female spot in another Morina flower, just on the right species, what happens?

They build up a static electric charge and the pollen jumps on them and helps spread that pollen from bloom to bloom.

And they get inside, and they get it all on.

So, that's 20 micrometers across, that pollen grain there.

But anyway, take a look at its pollen.

What these bees do is, they sit there. These solitary bees, they drill a hole in the ground or drill a hole in a branch, and they collect pollen and make it into a ball, and they lay an egg on it.

And it's really rather better not to mate with yourself.

First of all, pollen is tiny. Yes we know that.

Probably you are allergic to pollen or dust.

And the plant showers them with pollen, and off they go and pollinate.

These are the anthers of a lily, cleverly done so that when the unsuspecting insect lands on it, the anther flips up and whops it on the back with a great load of pollen that it then goes to another plant with.

Now with the pollination, it's a very serious issue for plants, because they move the pollen from one flower to the other, yet they cannot move from one flower to the other.

When they're out pollinating or gathering pollen from one flower, they stay to that crop exclusively, in order to help generate.

And there is as many different kinds of pollen as there are flowering plants.

At the species level, it's been estimated that insect based pollination, bees pollinating fruit and so on, is something like 190 billion dollars worth.

Like I said, pollen carries the male sex cells.

And of course, they're made to carry this pollen.

But pollen forensics can be very subtle.

And there's an orchid that might look to you as if it's got jaws, and in a way, it has it forces the insect to crawl out, getting covered in pollen that it takes somewhere else.

Those damn magnolias are in bloom again... and so is my hay fever.

Jonathan Drori Every pollen grain has a story

Here is a scanning electron micrograph of a grain of pollen.

So, what are pollen's properties? I hear you ask.

The pollen has little barbs on it, if we look.

And finally, in a rather grizzly way, the Bosnia war crimes some of the people brought to trial were brought to trial because of the evidence from pollen, which showed that bodies had been buried, exhumed and then reburied somewhere else.

That tells me that it's actually been fossilized, this pollen.

Pollen is tiny. It gets on to things, and it sticks to them.