![](http://www.alamy.com/thumbs/6/9C8F483B-55DE-4D38-BA77-8DB3FCA09391/CNYM71.jpg)
Old Man's Beard, Beard Lichen, Treemoss, Methuselah's beard lichen (Usnea spec.), at the twigs of a spruce
Size: 3431px × 5315px
Photo credit: © blickwinkel/Hecker / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., beard, bioindicator, bioindicators, branch, branches, coaction, commensal, conifer, coniferous, conifers, dependence, ecology, epiphyte, epiphytes, format, hecker, index, indicator, interaction, lichen, lichens, man, methuselah, organism, organisms, partnership, plant, plants, spruce, spruces, symbiosis, symbiotic, tree, treemoss, trees, twig, twigs, usneaceae, vertical, woody