Air plants, or epiphytes, complete part or all of their life cycle anchored or perched on another plant or structure rather than rooted in the soil. They obtain water and nutrients from dew, air moisture, rainwater and collected plant debris via adventitious (growing from the stem or leaf) and aerial roots. Epiphytes include many lichens and mosses, as well as 10% of all seed plants and ferns and over half the orchid species. This way of life isn't parasitic, in contrast to plants like mistletoe, which 'steals' nutrients from the host tree.

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