These plants are called Air Plants. Their true name are Tillandsia. The reason why they are nicknamed "Air Plants" is because they get the majority of their nutrients from the air around them.
These low-maintenance plants are the perfect little companions for home, work or school. They require very little up-keep, and are a nice green addition to brighten any setting regardless of the season. You can also find a plant that perfectly matches how much light they will receive.