What kinds of plants can be floated and would be well suited for a small betta bowl?

The only think I can think of would be Anacharis, although you'd need to be careful that it didn't obstruct the surface too much for oxygen exchange or prevent you betta getting to the water surface to air-breath

thanks, I was thinking of that too, but in the stores they have some weird moss stuff on top, I dont think its Java moss though.

You could try 'Duck Weed'. I have had that in my tank, but because of the filtration it swirlled around everywhere and most ended up in my filter, but if your bowl is calm the 'Duck Weed' would sit nicely on the water's surface

thanks, i'll look it up