Btw, the “tree seed” as you described had nothing to do with the initial concept and design of the helicopter.
Whoops☺
So you are saying that nowhere along the line of development of the helicopter did anyone observer, study or consider the properties of the maple seed natures most excellent example of autorotation? Seem odd to me but I will take your word for it, but in my defense I was apparently gave those engineers and developers more foresight than they earned