Usnea longissima Ach.
Methuselah’s Beard Lichen, Beard Lichen
Methuselah’s beard lichen, or another of the beard lichens, probably prompted J.R.R. Tolkein’s imagination when he created ents—ancient, slow-moving tree creatures in the Lord of the Rings trilogy.
Identification: All beard lichens are fruticose—that is, shaped like tiny branching shrubs. But only Methuselah’s beard lichen hangs in such long strips, pale yellowish-green in color, looking much like Spanish moss. Strands can reach lengths of almost 20' (6.1 m). The central chord is brownish or pinkish in color. Like many lichens, they are sensitive to pollution, especially to sulfur oxides released by some manufacturing processes, and populations are declining.
Usnea longissima at Stephen and Sylvia Sharnoff's lichen.com site
Usnea longissima on the Environmental Protection Agency's Endangered and Threatened Wildlife and Plants list
Usnea longissima on Key Nature
Usnea on Macrolichens of North America
Usnea longissima description by Thomas H. Kent, last updated 16 Aug 2013.