Seen close-up, the branched strands or tassels of beard lichen produce numerous short side-branches, thinner and paler than the long pendulous main branches. The branches may be cylindrical or flattened. Commonly found on trees, where they may hang or grow upright, these fruticose lichens resemble leafless shrubs, somewhat elastic in texture. Dry beard lichen burns readily.
As all lichens, beard lichens or Usnea species consist of one or two fungi in symbiosis with a photosynthetic green alga.
Usneas are sensitive to air pollution, especially sulphur dioxide. Their presence on some trees of a region is usually an indicator of clean air. Usnea longissima has become rare in the USA due to pollution. It is normally found in forests near bodies of water such as lakes or rivers (www.britannica.com; www.woodlandtrust.org.uk; www.fs.fed.us; Wikipedia).