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Beard lichens (Usnea spp.)

Dripping off the trees in clean-air woodlands, these bushy beard lichens adorn the branches and trunks and are some of our most conspicuous and beautiful lichens.

Lichens provide valuable ecosystem services such as carbon cycling and water retention.

Credit: Alastair Hotchkiss / WTML

You'll find Usnea ceratina growing mostly in the southwest of the UK.

Credit: Alastair Hotchkiss / WTML

Lichens on trees provide important micro-habitats, shelter and food for various small invertebrates.

Credit: Alastair Hotchkiss / WTML

Usnea filipendula is a species that grows in the north of the UK.

Credit: Alastair Hotchkiss / WTML

You'll find Usnea florida on old tree trunks in southern and southwest England, Wales and the Welsh Marches, northern England and Scotland.

Credit: Alastair Hotchkiss / WTML

Usnea articulata is also known as 'string of sausages lichen'.

Credit: Alastair Hotchkiss / WTML

Beard lichens are also known as ‘fruticose’ lichens, and they grow like mini shrubs or tassels on the bark of tree trunks and branches.

Credit: Alastair Hotchkiss / WTML

Beard lichens are intolerant of air pollution so only grow in woodlands with clear air.

Credit: Alastair Hotchkiss / WTML

Quick facts

Common name(s): beard lichen, old man’s beard, string of sausages lichen

Scientific name: Usnea spp. (including Usnea articulata, U. ceratina, U. cornuta, U. filipendula, U. florida, U. rubicunda, U. subfloridana)

Family: Parmeliaceae

Fruiting season: year-round

Habitat: tree trunks, branches and twigs often high in the canopy

What do beard lichens look like?

Lichens, or lichenised fungi, are organisms formed by the symbiosis of a fungus species and one or more other organism, usually an alga.

Beard lichens are known as fruticose lichens, which grow like mini shrubs or tassels anchored onto the bark of tree trunks and branches. They are all pale grey-green, and some produce striking disc-like fruit bodies.

Not to be confused with: similar looking lichens growing on trees, including the horsehair lichens, Bryoria and Alectoria species. Like beard lichens, these are intolerant of air pollution and Bryoria horsehair lichens have declined significantly over recent decades. They are less likely to be found than beard lichens across most of the UK, and horsehair lichens tend to be a bit finer, and often more brownish in colour.

Did you know?

Beard lichens once occurred on trees throughout the UK. But the impacts of past sulphur-dioxide pollution and continued nitrogen air pollution from agriculture have resulted in their loss.

Where to find beard lichens

Beard lichens can be found throughout the UK and Ireland, especially in areas with clean air.

The most widespread species occurring on twigs and branches is called Usnea subfloridana, and this has been recolonising woods and trees in the London and Midlands areas. But other species are typically found in different parts of the UK.

Credit: Alastair Hotchkiss / WTML

The pendulous Usnea ceratina and U. articulata (shown here and known as string of sausages lichen) can be seen in the southwest of the UK.

Credit: Alastair Hotchkiss / WTML

Usnea filipendula and U. hirta are the beard lichens that grow mostly in the north of the UK

Credit: Alastair Hotchkiss / WTML

The bushy Usnea florida can be found in well-wooded parts of southern and southwest England, Wales and the Welsh Marches, and northern England and Scotland. Look closely at the branches and twigs of trees in old woodlands.

Value to wildlife

Lichens play an important role in the ecology of woodlands. Lichens on trees provide valuable microhabitats, shelter and food for various small invertebrates.

These in turn are prey for larger insects and birds. They can also be hosts for other species of parasitic fungi. Lichens also provide many other ecosystem services such as carbon cycling and water retention.

Usnea looks very similar to the epiphytic flowering plant known as Spanish moss (which is neither a moss nor a lichen!).

Credit: Alastair Hotchkiss / WTML

Did you know?

Usnea species have been used medicinally for over a thousand years.

Uses of beard lichens

Most beard lichens contain usnic acid which is a potent antibacterial and antifungal agent.

It's effective against bacteria including Streptococcus, Staphylococcus and tuberculosis. It was traditionally used to treat wounds; Native Americans used it as a compress to prevent infection and gangrene.

It is also said to be edible and contains a high level of vitamin C.

Like many other lichens, beard lichens have also been used historically for dyes, to create orange, yellow, green, blue and purple textiles. Beard lichens have also been used to make cosmetics, preservatives and deodorants. In some areas, it was used as a fire-starter as it's flammable when dry and crisp.

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