Thanks for the info. All the tridents I’ve noticed and seen whether bonsai or landscape seemed to have smooth light bark that I can remember so I was curious about this tree. I like the shaggy brown bark on this one. I have one trident I bought with white smooth bark.It is definitely a trident maple.
Leaf shape changes as the tree matures. As you've found, young trees have the traditional 3 point leaves we are familiar with but as they get bigger and older the leaves change to the longer, spade shape.
Bark can vary with individuals and time of year. Some trees shed bark clean so have smoother trunks, some retain more older bark and end up looking shaggy. At the far end there's the 'arakawa' type where older bark is held firm so it ends up with thicker, craggy bark.
Keep growing seedlings from your tree. They make great bonsai projects and develop quite quickly.
I think @Shibui answered the question about trident. There are slight variations with them. Looks like a trident.I hope you don't mind me piling on RK. I have a very similar if not the same tree in my daughters back yard. This one show a reddish color to the flakey bark and leaves vary in shape on even the same branch. It has been planted there and non native I believe as all her other trees are.
She just sold the house so I'm happy I collected a couple seedlings this summer. Maybe Trident but?View attachment 453767
Mature Tridents have exfoliating bark. Bonsai people clean it off as it can look odd and can harbor insects. That tree is a trident though.Thanks for the info. All the tridents I’ve noticed and seen whether bonsai or landscape seemed to have smooth light bark that I can remember so I was curious about this tree. I like the shaggy brown bark on this one. I have one trident I bought with white smooth bark.