Planting in water instead of dirt?

I was given the task of "temporarialy housing" some plants that are living in a vase full of water, and was just asked to make sure they don't die...



I have no idea what kind they are, they are just kind of a creeping vine (very slow growing) with about 2x3 inch leaves. The entire root system is inside a vase full of water, no dirt at all.



Can you tell me what kind of plant this possibly is? I know, it's one of a zillion possibilities... Besides making sure the water level stays full, is there anything that I can do to make it grow better and prevent the random leaf death?

Also, what kind of plants can handle their root systems in water but their entire growth (body?) being outside the water? I thought that aquatic plants were entirely submerged, and other plants would die if they had too much water in their root system...



Thanks in advance!

Planting in water instead of dirt?
There are quite a few plants that can live in water only. The ones that I have in vases with water only are pothos plants. This is also how I start the roots on a clipping to get a new plant. Some I leave permanently in the water. The only care is to make sure that the roots stay in the water and they get sun light, Do not place in a window where the leaves can touch the glass and get burnt