Air PlantsOften growing far above the ground, "air plants" (or epiphytes) defy many of our common perceptions about plants. The majority use their roots only for attachment in the crowns of larger, usually woody plantsor to objects such as rocks and buildingsand derive moisture and nutrients from the atmosphere and by collecting falling debris. Only the mistletoes are true parasites. Epiphytes are not anomalies and there are approximately 28,000 speciesabout 10