I recently purchased a Rose of Sharon " Dianna." It had a few stray seed pods so I planted some seeds. Will these seeds produce true to the original or will they be a variation?
No, it will not be true. You are not true to your parents because of recessive or dominant genetics and the Law of Dominance.
Your ROS will be a ROS and good percentage of the seedlings might look like the parent, but they will not be "true". Only clones or cuttings come true.
Came across this link in helping my daughter with this concept.
Here is a link that might be useful: Mendel's Law