Spanish moss
Spanish moss is an epiphytic flowering plant that often grows upon large trees in tropical and subtropical climates. It is native to much of Mexico, Bermuda, the Bahamas, Central America, South America, the Southern United States, and West Indies. It has been naturalized in Queensland (Australia). It is colloquially known as "old man's beard" in several places, and known as "grandpa's beard" in French Polynesia. It has the widest distribution of any bromeliad.
From Wikipedia, licensed under CC BY-SA 4.0
Research Mentions
Spanish moss confirmed thriving on a Florida street tree
That gray, draping plant hanging from oaks in your neighborhood isn't a parasite killing the tree...