Usnea longissima
Methuselah's beard lichen
(c) B. Phalan, some rights reserved (CC BY), uploaded by B. Phalan · licence
Family: Parmeliaceae
Conservation status: CNPS 4.2
Usnea longissima (Methuselah's beard lichen) is a California plant in the Parmeliaceae family.
Methuselah's beard lichen is a California native lichen found in northwestern California, the North Coast Ranges, and Sierra Nevada Mountains in old-growth coniferous forests and woodland habitats at elevations of 300 to 2,000 meters. Hanging in long, intricate strands from tree branches, this pale gray to green-gray lichen forms delicate, pendulous clusters up to 2 to 3 meters in length. Growing as a highly elongated, branching thallus with fine, hair-like structure, it drapes dramatically from tree limbs like a silvery-green curtain. Its surface is characteristically smooth and somewhat translucent, with a fine, thread-like texture that allows it to sway gently in forest breezes. This remarkable lichen serves as an important indicator of air quality and ecological health in mature forest ecosystems.
Identification and appearance
Key characters: Differentiators are not available at this time.
Conservation status
CNPS 4.2
How to tell it apart
Differentiators are not available at this time.
Frequently asked questions
What plant family does Usnea longissima belong to?
Usnea longissima is in the Parmeliaceae family, genus Usnea.
Is Usnea longissima rare or endangered?
Usnea longissima carries California Rare Plant Rank 4.2, state rank S4.
Related species
Other California species in the same genus, family, or bioregion.
Sources: CDFW CNDDB
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.