The Home Depot here has some new stuff (to me anyway) with
Birch on one side and Maple on the other.

My quiz of the kid on the floor as to how to tell the difference
left him scratching his head.

The ply edge is labelled 'birch up/maple down', so I asked the
kid can I assume that that's 'right reading' so when you can read
the lettering, it means up for birch and down for maple. This could get confusing once the piece was sliced up.

He guessed that was so.

I was wondering what sort of a material that would make
for alternating tops and sides and what a clear varnish would
turn up on the two types of wood.

The stuff is on deal for $30/sheet.