Airplants (scientifically Tillandsia, read about them on Wikipedia here) are hardy, small plants that typically grow without soil. When displayed, they have a very minimalist look that is perfect for modern centerpieces. The best part: since they are live plants (not cut stems) you can keep them long after your wedding or give them to guests as favors. They require very little care, just submerge them in water for 1-2 hours per week. They can survive for two weeks without water, perfect if you lack a green thumb!