📍Usnea longissima, commonly known as “old man’s beard,” is a rare fruticose lichen.
🌳It primarily grows in cool-temperate to boreal-montane forests, hanging from the branches of coniferous trees in high-altitude regions with frequent fog.
It is considered the longest lichen in the world. While its stems typically range from 15–30 cm in length, specimens measuring 3–6 meters have been recorded. Its color varies from pale green to silvery yellow-green.
đź“•Air pollution and industrial logging significantly affect its metabolic functions, leading to a decline in populations. It is listed as critically endangered on the Red List.
đź’ŠTraditionally, it has been used as bedding and as a filtering material. Medically, U. longissima is recognized for its anti-inflammatory properties. It has been described in Chinese medicine as early as 500 CE.
📸 Photo by Juri Nascimbene – CC BY-SA 4.0
Italy, Veneto, Belluno, Val Visdende, Cadore 2007