Any Wood Connoisseurs Out There...

We know that all of the trim and baseboards in our house are mahogany, but we're trying to figure out if the staircase is also mahogany or something else.  Anyone out there know their wood grains??



I've googled a bunch of pictures but to be honest, I don't see a whole lot of difference between wood grains.  I don't have a trained eye so if anyone has any guesses, put your two cents in!  I've never really heard of a mahogany staircase, it seems they're usually oak or something, so I'm assuming its not, but you never know! 

Tonight I'm hoping to do a bit of wood filler on the many many gauges in the steps, so I'll be sure to let you know how that goes!