The key thing is, if you are playing a stroke and hit the tree then continue your swing and hit the ball then there is no penalty. If you are taking a practice swing and knock a leaf off then one shot penalty.
KNOCK KNOCK! Who's there? LEAF! Leaf who? LEAF ME ALONE!
Leaf
tree leaf
an oak tree leaf duuh
knonk knock open the door foook!
If the wind is a hurricane strength wind it can knock down a palm tree. Regular strength wind, keeping in mind the palm tree is healthy can't knock down a palm tree.
Canada. It's a leaf from a Maple tree.
tree
An ash-leaf is a leaf of an ash tree.
It was believed that trees had spirits and to invoke those spirits you would tap on the tree, "knock on wood". The practice tended to be a way to ask the spirits to intervene and save you from a bad out come (bad luck). This is why when you say something you do not want to come about you "knock on wood."
A leaf is neither. A cherry tree is a hardwood.