Saw an interesting bush in South Carolina. It had an inedible apple-like fruit, but nobody knew the name of it

Question

The plant flowers in spring and bears the fruit in late summer.

Answer 1

Without a picture of the bush it would be just a guess but I have a quince bush that has pink flowers in the spring and has fruit that looks apple like. The fruit is edible though. People make jelly out of them.

Answer 2

hedge-apple?....

http://hedgeapple.com/