beard moss(n = noun.plant) beard lichen, usnea barbata - greenish grey pendulous lichen growing on trees;
is a kind of lichen
is a member of genus usnea, usnea

acrocarpous moss, arctic moss, beard, beard lichen, beard worm, black moss, bog moss, broom beard grass, club moss, crown beard, goat's beard, golden crown beard, iceland moss, imperial beard, irish moss, jupiter's beard, lion's beard, little club moss, long moss, moss, moss agate, moss animal, moss campion, moss family, moss genus, moss green, moss hart, moss locust, moss phlox, moss pink, old man's beard, peat moss, pleurocarpous moss, reindeer moss, rose moss, scale moss, sea moss, spanish moss, sphagnum moss, spike moss, staghorn moss, vandyke beard