Trentepohlia abietina

Trentepohlia abietina is an alga that forms bright orange or orange-brown patches on tree trunks.

View under the microscope of the reddish, short filaments of swollen or elliptical cells of Trentepohlia umbrina. © P V York

The orange-red pigment protects the alga against intense sunlight.

This alga is easy to find in the more humid westerly parts of the British Isles.

Its relatives - including Trentepohlia iolithus - form unsightly red streaks on buildings.

Trentepohlia is the most common algal genus in lichens.

Species detail

Taxonomy

Trentepohlia abietina forms felt-like patches on tree trunks. Find out what gives the patches their texture.
Distribution

Trentepohlia abietina usually grows on tree trunks. But where?
Biology

Trentepohlia abietina is widely distributed. Find out how this alga reproduces.
Conservation

Trentepohlia species are not harmful to trees but are often considered an unsightly nuisance. Find out where.
References

Get reference information for Trentepohlia abietina.

Images

Distinctive orange coloured covering of the Trentepohlia abietina on trunks of two ash trees near Toys Hill, Kent.

Close view of the orange felt-like covering on tree bark of Trentepohlia abietina.

Reddish colouration caused by the crustose covering Trentepohlia umbrina on the bark of an apple tree in Scadbury Country Park, Bromley, Kent.

The reddish discoloration of the wall of a suburban house in Galway City, Ireland caused by Trentepohlia iolithus. It is known locally as ‘red rust’.

Orange-coloured patches of Trentephohlia abietina on a tree trunk along with grey-coloured crustose lichens.

Close view of red-coloured patches of the crustose Trentepohlia umbrina - sometimes grows with T. abientina and confused with it.

Print version

Author

Professor David John
Scientific Associate
Department of Botany

A word from the author

"My attention has been drawn to Trentepohlia abietina by lichenologists and amateur naturalists who have noticed, in recent years, an increase in the number of orange-red tree trunks in south and south-eastern England. It is only possible to speculate on the reasons for the increase in Trentepohlia - perhaps decreased pollution, short-term climatic change - until such time as a systematic research study is undertaken."