Usnea (Usnea barbata): Traditional Uses & Safety

At a glance

Botanical name: Usnea barbata
Family: Parmeliaceae
Part used: Thallus (whole lichen)
Taste: Bitter
Temperature: Cool
Moisture: Dry

No pre-1900 source found for this exact plant. The old books speak of tree moss as a group and say its quality changes with the tree it grows on, and the one writer who names Usnea is passing on Galen.

Safety at a glance

In pregnancy

Insufficient data; avoid

While breastfeeding

Limited data; avoid during breastfeeding as precaution — usnic acid hepatotoxicity concerns.

For children

Avoid under 12

Cautions

Hepatotoxicity reported with isolated usnic acid supplements; whole plant safer; liver caution

General contraindications

Insufficient safety data; avoid

Stewardship

Usnea grows as lichen on old-growth tree bark; SLOW-GROWING (millimeters per year). Ethical harvest: take only from fallen branches, never from living standing trees. Stewardship: the pace of lichen growth demands the slowest wildcrafting — a test of patience.

In the traditional record

Usnea (Usnea spp.) — long-standing folk remedy across Northern European, Native American, and Chinese traditions for infections, wound dressing, and respiratory complaints; used in ancient Egyptian mummification and recorded in Traditional Chinese Medicine as Song Luo for damp-heat conditions.

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Educational use

The Apothecary is educational and does not constitute medical advice. Nothing here is intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare provider before changing what you take, especially if you are pregnant, nursing, taking medication, or managing a diagnosed condition.

On our sources

These entries draw on public-domain materia medica, most of it published before 1900, alongside a smaller number of modern reference works. Energetic qualities such as warming, cooling, drying and moistening are a traditional framework for describing how a plant behaves in the body, not a laboratory measurement. Where a period source states one, we cite it. Where none does, and for many North American herbs none exists, the value reflects modern herbal consensus rather than a historical text. When we cannot support a caution with real evidence, we say nothing rather than guess.