Cladonia floerkiana lichen (photo: Dave Purchase)


Under development. Contributions from BFC members welcome. Watch this space.

About lichens

Lichens are one of the earliest forms of life to have evolved on land. They are present on every continent, including Antarctica.

Lichens: symbiosis between fungi and algae and/or cyanobacteria

Lichens are symbiotic life forms. That is, a lichen is not a single life form, but a stable mutual association (a symbiosis) between a fungus and algae and/or a cyanobacteria. The algae or the cyanobacteria (the photobiont) provide sugars to the fungus through photosynthesis, while the fungus (the mycobiont) provides shelter and mineral nutrients to the algae. There are over 2,000 species identified in Britain alone, and hundreds of thousands throughout the world.

Lichen forms or morphology

Lichens come in a number of different forms, which are mainly determined by the fungal component, the thallus. These are: Leprose, Filamentous, Crustose, Placodioid, Squamulose, Foliose, Fruticose and in combinations of these.


The thallus forms a more or less diffuse powdery mass, usually with little or no structure. Some crustose forms may be entirely covered in powdery soredia (small propagules containing a few algal cells and fungal hyphae).

Examples: Lepraria incana.


The thallus forms a very fine, soft, hair-like mass which may be gathered into a felt-like mat of fine filaments. 

Examples: Ephebe lanata.


The thallus forms a crust with only the upper surface visible, and which can usually only be removed with part of the substratum on or in which which it is growing (e.g. wood or rock).

Examples: Arthonia radiata; Lecidella elaeochroma.


Lichens in the High Peak

For these buttons with the solid borders to work properly you will need to be registered and logged into iNaturalist. This is a free and extremely useful app. See our ‘How to record wildlife’ page for more information and tips on how to use it.

Takes you to the up-to-date list and photo galleries of all fungi and lichen observations within the High Peak area, as recorded on iNaturalist

Takes you to the up-to-date list and photo galleries of all fungi and lichen observations within the ‘Buxton polygon’ area, as recorded on iNaturalist and collected by the Buxton Biodiversity Recording Group project

Steve is an expert in the fascinating field of lichens, and has an excellent set of albums of lichen photos on his Flickr account. These are well worth a visit, and an invaluable aid to those who love lichens but struggle to identify them. Steve has kindly made them available to use here.

A page of photos of lichens taken during the BFC walk lead by Steve on 22nd April 2022.

Identifying lichens

Lichens: An Illustrated Guide to the British and Irish Species (7th Edition)

Frank S.Dobson

The British Lichen Society

The lichenologist’s ‘bible’ for identifying British and Irish lichens. Suitable for amateurs and more advanced lichenologists, and compact enough to be used in the field.

The Field Studies Council (FSC) publish a very useful range of laminated guides to lichens of various habitats, e.g. urban, and heaths and moors.

Information and guidance

The British Lichen Society welcomes all who are interested in lichens, whether you are a complete beginner or someone with a life-time’s experience of lichenology. Throughout the world, but with a special emphasis on the British Isles, their aims are:

  • to promote and advance the teaching and study of lichens;
  • to encourage and actively support the conservation of lichens and their habitats;
  • to raise public awareness of the beauty of lichens and of their importance as indicators of the health of our environment.

They work towards these aims through field meetings, workshops and recording projects. Their Bulletin is packed with information about lichens, lichenologists and events, and they also publish a highly regarded scientific journal, The Lichenologist.

Private Facebook group that you can join on application, for sharing of members’ own photos and identification. International membership (57k members).