a tree nut
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...
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.
An acorn is the nut of the oak tree.
An acorn is the seed of the Oak tree.