Spanish moss

a rootless epiphytic plant (Tillandsia usneoides) of the pineapple family, often found growing in long, graceful strands from the branches of trees in the SE U.S. and tropical America

See Spanish moss in American Heritage Dictionary 4

noun
An epiphytic bromeliad plant (Tillandsia usneoides) of the southeast United States and tropical America, having gray threadlike stems drooping in long, densely matted clusters.
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