Although we are taking about silver maple I have a handful of red maples I'm developing as well. To be honest most of my silver maples are probably red maple silver crosses of varying degrees because they all seem to display red maple characteristics especially leaf shape. All the true silver maples you see in nursery stock doesn't really display the varying leaf characteristics like wild grown silver maples. At times I've almost new I had a red maple then the silver maple leaf pop's up the next growing season to leave me confused
. I've tried everything to discern or Distinguish the two from each other to no good results. Bud shape nope... leaf shape,, big nope.... bark color nope...you could almost Certainly tell the difference when the tree's start to really bark up because silver maple have that Flaky bark that comes off in little strips. But who among use has tree's old enough to see real bark formation besides maybe you..when they are younger Material they might as well be the same tree is how I look at them.