There are very few house plants that will survive long term emmersion. Terrestrial plants are often sold as aquatic, simply because they 'last' longer in tanks not approriate for plants than true aquatics. Terrestrial plants go into a stasis when submersed, and live off their stored nutrients. Many can maintain this for several months, while true aquatics in a nutrient-poor, low light tank typically die within a few weeks.
However--there are many plants than can be grown successfully with just the roots hanging into the water. It can be tricky to accomodate them, but I've kept spider plants, peace lilies, wandering jew, and yes, snippets of christmas cactus this way unti lthey developed enough roots to be planted. I wouldn't do it full time, because it's kind of a pain in my setups. I'm going to work on getting some little plastic rings to support plants and try putting them in my frog tank--open topped, so no canopy to limit upward growth.