Usnea florida is a species of beard lichen in the family Parmeliaceae. First described by Carl Linnaeus in 1753 and later reclassified by Friedrich Heinrich Wiggers in 1780, it is a shrubby, upright lichen growing 2–10 cm tall with slender, curved branches covered in papillae and fibrils, and distinctive disc-shaped reproductive structures (apothecia) surrounded by branching filaments. Its development progresses through eleven distinct states across four main periods, beginning with the union of fungal spores and compatible algae to form a protothallus, followed by branching processes that create its characteristic bushy structure, and eventually producing reproductive apothecia in its generative stages.

The lichen predominantly colonises smaller branches and twigs in the upper canopy of broad-leaved trees in well-lit environments, particularly in mountain forests that experience frequent fog. Despite being locally common in certain regions of Europe, including southern and western Britain, the Polish Eastern Carpathians, and Italian mountain forests from the Alps to Sicily, populations of Usnea florida are declining due to elevated atmospheric ammonia concentrations, resulting in critically endangered status in several European countries.

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