The Aponogeton undulatus will develop white flowers when the tips of the plant becomes emersed from the tank. Really nice looking. Only problem is this plant grows like a weed and you'll have a gateway for shrimp (amanos) to get out of your tank if you let it flower emersed. This is what happened to me but other than that, really nice plant. I also have the long lace java fern, nice plant too.