I've had my planted tank set up for about a month now an I'm starting to wonder about this plant. Is it aquatic? What is it? It came as a "bonus" with my shipment.
It's the one in the back, the tall thin one. The roots almost look like there is a bulb there.
A good guide to non-aquatic plants is that they will support their own weight out of the water, i.e. will stand upright. True aquatic plants have adapted to use the water for support, hence if you take them out they flop over. This is true for say 90% of aquatic plants, there are some exceptions, some species of Hygrophila for example.