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Why do strawberries have seeds on the outside?

Living is easy with eyes closed
"Which is the only fruit with the seeds on the outside?" I saw this question in a kids' magazine or perhaps a bubble gum wrapper, and the answer was "strawberries." What could be the biological significance of this? I wondered while munching on some at breakfast.

Misunderstanding all you see
Seems it was a bit of a trick question. The little specks (about two hundred on average) that I assumed were seeds are called achenes. Each achene is an individual fruit with a single seed inside. The thing we call a strawberry is not a berry in the botanical sense, and some say not even a fruit. It is accessory tissue for an aggregate fruit, formed from multiple ovaries of one flower.

It's getting hard to be someone
Plants can have sex lives so complicated they might make a good reality TV show. Strawberries can be hermaphroditic, with male and female parts, or with distinct genders. They do not even rely on seeds to reproduce. They can send out skinny "runners" that take root and start a new plant. Commercial strawberries are mostly infertile hybrids, propagated by runners.
 
But it all works out
In the wild, strawberries and other colourful "frooty" items, tend to attract visual frugivores, like birds. When said creature eats the fruit, and spits up or poops out the seeds, the plant starts its next generation. Except, of course, when the animals are people who use toilets. 
 
It doesn't matter much to me
Perhaps having seeds or achenes on the surface of the tasty bit, would increase the chances of getting spread around. A little bird might just take a little nibble and still pick up some seed to spread. Seeds surrounded by good stuff might be more likely to be left behind. I have not been able to find any experimental or theoretical work on this, but I would be interested in hearing what you have to say on this idea.
 
Sites to check out:
Strawberry achenes
Growing strawberries 
Drawings of strawberries developing
Strawberry reproduction
Strawberry etymology
Growing strawberries
Strawberry genetics
A germinating strawberry
 
Are you growing strawberries? We're experimenting with strawberries by growing them as part of the vertical garden in the Ken Spencer Science Park. Check them out on your next visit!