Why do some fruits have a groove on the side them?

Hmm. Probably because the fruit meat grows around a large, central seed (the pit found in peaches and plums).

Hmm.. but avocados don’t have a groove in them and they grow around a large pit/seed.
Now I’m curious..

That’s so they’ll fit in the slingshot.

Could be a different case… Avocadoes actually fit in as a berry… Like a cherry.

Damn, I was shocked when I found out avocados were a fruit. Now I find out it’s a berry… very strange.

Is it possible that peaches are dicots (like beans)? This means that they have two halves to the seed.

This groove is called the “ventral suture”, and is a vestige of the structure of the carpel (the central seed-bearing organs of the flower).

In some flowers, the carpels are composed of multiple segments that are fused along their edges to form the protective envelope where the seeds will develop. In the case of the fruits you’re talking about, especially members of the genus Prunus (plums, peaches apricots, cherries…), the carpels have one segment that folds around and seals at its single edge. It is this suture that appears in the mature fruit as a groove

Wow! All this time I thought a berry was a fruit! I learned something new today thanks to fluther.

Hooray for Harp!

Maybe it’s like when some dudes have ‘seams’ on their naughty bits. :-p

I need sleep.