Have you ever seen a fig flower?

Have you seen a fig flower?

By Dr Anina Lee

Of course you have – you’ve seen lots and lots of them. Every time you break open a lovely lush fig you see the flowers inside. A fig is actually the stem of an inflorescence, very enlarged and fleshy, that surrounds the tiny flowers inside. And the crunchy bits under your teeth are the seeds.

Fig trees are unique in that their flowers are completely concealed within an enclosed inflorescence, with the hundreds of tiny florets lining the inside of a central cavity.

So if the flowers are hidden from view, what pollinator would visit such an un-showy non-flower? How does it get pollinated? Well, this is the really interesting thing about figs. A unique flower requires a unique pollinator. All fig trees are pollinated by very small (female) wasps of the family Agaonidae. These little wasps are just able to squeeze through the tiny hole on the front of the fig. Sometimes the squeeze through the little hole on the front of the fig is so tight that the wasp loses its wings in the process – but no matter, because it will never leave the fig again.

The wasps are so specialised that each species of wasp only pollinates a particular species of fig tree. As the song says: “You can’t have one without the other”. This is an example of obligate commensalism, developed over around 60 million years of co-evolution.

The whole story is further complicated by the fact that some fig species are monoecious and some are dioecious. Monoecious means that the trees produce figs that have both male and female flowers. Dioecious means that the species has trees that produce figs with only female flowers as well as trees that produce figs with only male flowers.

Click on the newspaper below to read more (see page 18).