Dolichousnea longissima

Methuselah's beard lichen
Scientific classification
Domain:	Eukaryota
Kingdom:	Fungi
Division:	Ascomycota
Class:	Lecanoromycetes
Order:	Lecanorales
Family:	Parmeliaceae
Genus:	Dolichousnea
Species:	D. longissima
Binomial name
	Dolichousnea longissima; (Ach.) Articus (2004)
Synonyms
	Parmelia coralloidea var. longissima (Ach.) Spreng. (1827); Parmelia longissima (Ach.) Spreng. (1827); Usnea barbata var. longissima (Ach.) Schaer. (1850); Usnea longissima Ach. (1810);

Dolichousnea longissima (syn. Usnea longissima), commonly known by the names old man's beard or Methuselah's beard lichen, is a fruticose lichen in the family Parmeliaceae.