St Mary’s Church – an introductory lichen trail

Churchyards are important mini nature reserves.  Their value for wildlife is often underappreciated.  The variety of ancient stones and the surrounding grassland and trees can shelter many species that may no longer have other suitable habitats nearby.

Lichens are amazing small organisms. They are each a combination of a fungus and an alga living symbiotically together in places where neither could live alone, such as on dry stones.

Mosses are sometimes confused with lichens, but they are tiny plants with green leaves – one common moss is featured on this trail.

To appreciate the beauty of lichens, it helps to use magnification.  If you don’t have a hand-lens, you can easily zoom in with a mobile phone camera (holding the phone about 10 cm from the stone may be necessary for a sharp focus on the lichens).

This note has been prepared by Dr Di Napier as part of The Making of Tysoe Project, on behalf of the Tysoe Heritage Research Group. Except where otherwise mentioned, all the photos were taken by the author, using a mobile phone.

Lichens in St Mary’s Churchyard

1. Golden Circle Lichen (Caloplaca flavescens)

Bright yellow narrow-lobed edges, often with a whitish zone just inside the yellow outer rim.  The centre often falls out as it gets older.  The orange-yellow ‘jam-tart’ fruits produce spores that can begin new lichens once spread by rain, wind etc.  Common on calcareous stone.

2. Chewing-gum Lichen (Lecanora muralis)

Grey-green flattened lobes around the edges, with brownish ‘jam-tart’ fruits towards the centre. Common on tarmac paths, and often mistaken for chewing-gum.

3. Warted Golden-frill Lichen (Xanthoria calcicola)

Rich golden yellow circles with frilled edges, with warty bumps in the central part.  Fairly frequent on calcareous stone, but less common than Golden Circle Lichen, (Caloplaca flavescens).

4. Grey Lava Lichen (Diploicia canescens) 

Pale grey or white (sometimes greenish under trees), with wrinkled edges like solidified lava from a volcano.  Common on basic and nutrient-enriched stones and trees.

5. White-paint Lichens (Aspicilia)

Large thin white patches that look like spilt paint.  The dark spots are the fruiting bodies that produce the spores.

6. Lemon Crumble-crust (Candelariella medians) with Golden Circle Lichen below

Small crumbly crusty patches of distinctive pale yellow. Often without fruiting bodies. Found on calcareous stones.

7. (A moss) Silky Wall Feather-moss (Homalothecium seríceum)

A common but elegant moss often found growing on walls and paths

8. Curled-edge Rosette Lichen (Physcia tenella) and Common Yellow Lichen (Xanthoria parietina) 

This young cherry tree already has at least half a dozen different lichen species colonising the bark. They do not cause any problems for the tree.  Physcia tenella (grey) and Xanthoria parietina (yellow) are both very common on trees and hedges in areas with high nutrient levels from farming.

9. Orange-dot Lichen (Protoblastenia rupestris) 

This table-top tomb has a wonderful mosaic of different lichens – how many can you spot?   Orange-dot Lichen has a thin pale background crust, with orange fruiting bodies without distinct rims around the edge.

10. A variety of lichens on an early 18^th-century headstone

Click to refer to first illustration, above.

Websites about lichens
The British Lichen Society website: https://britishlichensociety.org.uk
Another very useful website is Dorset Lichens – although the majority of photographs are from Dorset, most of the featured species are also found in Warwickshire. https://www.dorsetnature.co.uk/Dorset-lichen.html

Printed leaflets and books about lichens
Field Studies Council Guide to Common Churchyard Lichens – a laminated fold-out leaflet.
Field Studies Council Wildlife Pack 20: Lichens (includes the churchyard sheet).
Lichens: An Illustrated Guide to the British and Irish Species by Frank S Dobson.

Very few lichens have English names. Here are some memory-jogging invented English names that may help beginners tune into some of the distinctive features:
1: Golden Circle Lichen (Caloplaca flavescens)
2: Chewing-gum Lichen (Lecanora muralis)
3: Warted Golden-frill Lichen (Xanthoria calcicola)
4: Grey Lava Lichen (Diploicia canescens)
5: White-paint Lichens (Aspicilia)
6: Lemon Crumble-crust (Candelariella medians)
7: (a moss) Silky Wall Feather-moss (Homalothecium seríceum)
8: Curled-edge Rosette Lichen (Physcia tenella) and Common Yellow Lichen (Xanthoria parietina)
9: Orange-dot Lichen (Protoblastenia rupestris)

Di Napier June 2022