Dolichousnea longissima

Methuselah beard lichen or old man’s beard lichen (and known often scientifically by its synoynm, Usnea longissima) was once more widespread than it is today. Throughout much of its historic range, a patchy distribution of circumboreal forests in Europe, Asia and North America, it is now either threatened or extirpated. Populations remain strong in the Pacific Northwest of North America, however. Declines are attributable to habitat loss (clear-cutting) and air pollution.

In one of my favourite natural history books, The Lichens of North America, reference is made both to its pollution-sensitivity: “Its presence can be used as an indication of pure air” as well as its outstanding potential length: up to 3m (10ft) (“easily the longest lichen in the world“).

A photographic note: the vertical streaks in the background of the image are rain drops.

Dolichousnea longissima

24 responses to “Dolichousnea longissima”

  1. Meg Bernstein

    So graceful!

  2. Marijke

    When I see these amazing lichens, I feel like I’m in another world.

  3. Keith

    Thank you Daniel. Very beautiful.

  4. Rob

    Very nice and delicate. I will watch for it in the forests.

  5. Mary Ann, in Toronto

    Gorgeous. I’d love to see this in real life.

  6. Bonnie

    Wow, this is totally cool! It doesn’t look like a beard to me; more like mohair yarn. Is it as soft as it looks?

  7. Betty

    How beautiful! Is this related to the “Spanish Moss” found in parts of Florida?

  8. Anne

    The lichen is really beautiful and looks like something I’d knit with, but I’m wondering about the shrub it’s on. It looks like a buxus to me but that doesn’t seem right. Anyone?

  9. Melissa

    I, too, was wondering about a possible relationship with “Spanish Moss.” I’ve lived all over the SE U.S. (S.C., N.C., Ga., Fla.), and it’s everywhere, beautiful, but filled with little red bugs. People here bake it to kill the bugs and then decorate indoor and out with it. Read or heard anything yet, Betty?

  10. annie Morgan

    Aside from the plant subject alone, this is a very beautiful photograph.

  11. stuart

    It may look like Spanish Moss, but it’s not at all related. Spanish Moss, Tillandsia usneoides, is a member of the Bromeliaceae, the same family as the pineapple. There is some nominal connection, as the genus of this plant is Usnea, and the specific epithet of Spanish Moss is usneoides. Don’t know what that means, though.

  12. Daniel in Princeton

    This isn’t Spanish Moss (Tillandsia usneoides), which is a bromeliad. But the similarity is such that Spanish Moss is potentially the only vascular plant to be named after a lichen (usneoides means Usnea-like), since Usnea would have been more familiar to Old-World botanists like Linnaeus (who named T. usneoides) than the New World Spanish Moss. Both are quite beautiful components of forests. And both are impressive epiphytes, able to draw moisture and nutrients from the air, and as such grow rootless.
    A number of Usnea species do get used as dyes for yarn, although not as yarn itself, the lichens are soft when moist, but get rather hard and brittle when dry.
    Thanks for posting the picture, as a grad student studying the interactions between plants and fog, Usnea holds a particularly dear spot in my heart.

  13. Tammy

    really beautiful! It startling how much it looks like spanish moss- but softer. Interesting that it’s stiff when dry, and used as yarn dye.

  14. Andy MacKinnon

    A beautiful photo, that supports the speculation that this lichen or a close associate may have provided the inspiration for tinsel on our Christmas trees.

  15. Daniel Mosquin

    Anne, it is likely either a willow (Salix) or a member of the genus Prunus. This was a narrow row of trees growing along the roadside between the road and an open wet meadow where I saw Roosevelt elk the night before.

  16. C.Wick

    Daniel, a gorgeous photo! Really makes me want to move up North more and more each day. Our lichens down here in Kansas seem so ‘boring’ when compaired to these wonders.

  17. elizabeth a airhart

    i also live in florida tis not like
    the spanish moss draped over our trees
    or me if you stand still long enough
    i found an intersting site while googling
    danwinkler -fine pictures from the land of the
    umber dragon bhutons
    and a folk tale that this is thoughtt to manifest
    itself as human beings to help humans on to the path of wisdom a nice site to visit thank you

  18. kelly

    beautiful shot! i’m doing a cultural assessment of a northern bc gitxsan territory area near hazelton,bc and there is plenty of old man’s beard growing in the old growth areas. promising thought that it indicates “pure air”. i’ll be breathing more deeply there from now on. thanks!

  19. Kate

    That’s soooooo pretty!

  20. Eric Simpson

    Beautiful shot, Daniel, and it really highlights the delicacy of the strands. I’ve spent a fair amount of time in the state and national redwood parks in California, especially Prairie Creek, and the old man’s beard can reach astonishing lengths and densities in the riparian areas. It’s so much like walking through a fairy wood, that I half expect to see brownies peering through the layered strands from the overhanging branches.

  21. Sam


  22. Richard Droker

    Lighting, moisture and composition make for a quintessential image of this lichen.
    Although Usnea longissima was placed in Dolichousnea by Articus in 2004 my impression is that the change has not been accepted. (Wirtz et al. (2006) looked at Neuropogon and do not agree with Articus (2004) for that group, and they further state “We recommend a conservative approach regarding nomenclatural changes from phylogenetic studies especially at the generic level when few taxa are studied.”) The North American Checklist and all recent literature have continued with Usnea longissima.

  23. Harold Benson

    Is this plant medicinal….i need a reply.tnx

  24. Daniel Mosquin

    Some discussion regarding purported medicinal properties on Wikipedia (and Google Scholar): Usnea.

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