The sex life of bananas

OK, cheap trick. The smooth, yellow bananas that we eat (Musa cavendish) don't have a sex life at all, because they are bred to be seedless and hence sterile.

But their wild ancestors, such as Musa acuminata, do.

M. acuminata is chiropterophilous--your word of the day--which means it's pollinated by bats.

A bit creepy, no?

Bat-pollinated plants flower at night, because, of course, bats are nocturnal.

The flowers tend to be placed at a distance away from the rest of the foliage (you can see this in the M. acuminata flower, which hangs at a distance from the leaves), because it makes it easier for the bat to access. That's also why you see the red bract curled up, coyly revealing the flowers.

The flowers have to be relatively large to be able to bear the weight of the bat.

And to attract the bat, the flowers must produce a bat signal. Bats rely on echolocation to find flowers, so those flowers that return the "loudest" echoes to the echolocating bat are most successful in attracting it. In return, they must reward the bat with lots of sweet, sweet nectar (or it won't be back the next time).

Bats actually make great pollinating agents because being larger, they can carry a lot of pollen over long distances. But they are expensive to feed. It takes a lot of energy for a plant to produce a flower as large and sweet as the banana flower, so a plant is not going to go to the trouble (chiropterophily is an evolutionary adaptation) unless it faces significant challenges to reproduction.

Chiropterophilous plants thus tend to be ones that grow in low density and fragmented environments, like M. acuminata.