Methuselah's beard lichen, also known as Usnea longissima Ach., is part of the family Parmeliaceae, a fungi. Native to parts of the Americas (Alaska, Wisconsin, Yukon), Norway (Southeastern Coast) and Sweden.
To view the official taxinomical report for the Usnea longissima Ach. visit www.itis.usda.gov. Common descendants of the Methuselah's beard lichen include, Usnea longissima corticata, and Usnea longissima longissima.
Not currently endangered, but extremely rare because of its peculiar growing conditions. Not really edible, though, not listed as toxic, something I think most people wouldn't really want to eat, since it isn't really very pretty.
A fruticose lichen, meaning it grows with a bushy, stalked, or pendant habit. Preferring old growth conifer forests, the Methuselah's Beard lichen is a rare find, but abundant in the places it does grow. This lichen spreads by taking small chunks of it to a suitable area, where it spreads profusely. The only known practical use for Methuselah's Beard lichen is as a make shift cheesecloth for aboriginal peoples. It was used to strain pitch that was used as medicine.
About five to fifteen inches long, yellowish green in color, and long and stringy, this lichen tends to grow in long unbranched dangling sections. It grows with one central branch, which tends to be white, and lots of short off shoots, which are normally the yellowish green in color. When on the search for this lichen, try old growth forests in cooler northern areas. Good luck!