An acorn is the nut of the oak tree.
An acorn is the seed of the Oak tree.
The early CA native populations to use eat them. They would ground them, poor hot water over them to get the acid out, and then make them into a tortilla type of food and heat them over hot rocks. I...
a tree nut
generally, an oak tree is around 20 years old before producing acorns; but, some have been known to grow to 50 years before producing acorns.