Q.what does a graft knot on a weeping cherry tree look like
I bought a weeping cherry tree 2 summers ago, last summer a branch started growing straight up in the air. I read your article on what to do and it said not to prune it as it will eventually weep. I didn’t think it was a grafted tree. The branch is thicker now and taller and is not showing any signs of weeping. We will prune it either way this fall.
We looked for a graft knot and didn’t see one that we know of. Could the branch have grown out of this knot?
The close up picture is of the branch growing out of the tree. The last picture is the other side of the tree, not sure of that looks like a graft knot or not.

The graft should look like a knot in the wood.
These articles will help you.
https://www.gardeningknowhow.com/ornamental/trees/weeping-cherry/cherry-tree-no-longer-weeps.htm
https://extension.unh.edu/resource/growing-fruit-grafting-fruit-trees-home-orchard-fact-sheet