In unpolluted churchyards, lichens often form mosaics of colour, especially on the stonework, adding to the character and interest of the site. They vary in form from simple, powdery scatterings and crusts to more elaborate leafy or even bushy structures.

Lichens are two 'plants' in one: a fungal partner usually forms the visible body of the lichen and within, protected by threads of fungus, cells of algae provide nutrition, utilising sunlight in the same way as green plants. Contrary to popular opinion, lichens do not 'feed' on the stone, bark or soil upon which they grow. They reproduce by means of microscopic spores capable, on finding a suitable algal partner, of colonising most surfaces which are reasonably stable and not too shaded or smooth. These spores are released from fruiting bodies which are typically disc-shaped and, when viewed through a hand-lens, resemble miniature jam tarts. Lichens may also propagate themselves by means of powdery outgrowths, minute projections or fragments which are scattered in the wind and rain or dispersed by small creatures.

• Churchyards are of supreme importance for lichen conservation, particularly where there are no natural outcrops of rock.
• Churchyards provide an excellent environment for the study of lichen biology and colonisation.
• Of the 1700 British species, over 300 have been found growing on churchyard stone in lowland England.
• Almost half the species are rare, having been noted in fewer than ten churchyards. Some seldom occur in any other habitat.
• Many churchyards are found to have well over 100 species.

Provided there is sufficient light and moisture, lichens are able to colonise surfaces mostly unsuitable for flowering plants. They grow very slowly, sometimes no more than half a millimetre a year, and many are long-lived. Individual lichens may well be almost as old as the gravestones upon which they live. The ancient stonework of churches and churchyards, when undisturbed and unpolluted by chemical sprays, thus provides a sanctuary for them. The geology is often varied: limestone, sandstone, ironstone, marble, brick, mortar, slate and granite, each having their distinctive lichen communities. The tombstones, the stone surfaces of the boundary wall and of the church itself vary also from rough to smooth, shaded to exposed, damp to dry, horizontal to vertical, providing a multitude of niches. For example, the lichens on the shaded north side of the church and those on the sunny south side are markedly different. Further micro-habitats are provided by recessed lettering, soil crevices in boundary walls, sills stained with iron and copper, and the granite chippings within a kerbed grave. In addition, lichens are to be found on well-established trees, wooden structures such as seats and fences, grassy areas, pathways and even rubber dustbin lids!

A balanced churchyard management plan is beneficial to all forms of wildlife. Neither fastidiousness nor neglect serve the lichen well. Spraying around the base of tombstones to discourage 'weeds' may damage existing communities and leave unpleasant stains. If, on the other hand, memorials are left to disappear under a sea of bramble, ivy or cow parsley, the lichens on them will wither and die through lack of light. Grass cuttings left to rot on low chest tombs and kerbs will have a similar detrimental effect. Damage to stonework by lichens is minimal. Walls and tombs built of good quality stone have shown little deterioration, other than that caused by natural weathering, in hundreds of years. Indeed, a good covering of lichens may protect them. The most obvious colonisation tends to occur on the tops of tombstones enriched by bird droppings. Sometimes, lichen growth emphasises an inscription. At other times, it may obscure certain details. Where cleaning is felt to be necessary for an inscription to be made legible, this can be achieved by using a soft brush and plain water. Spraying with pesticides or vigorous scrubbing may well cause more damage to the stone than any lichen colonisation, and the result is unsightly. If, for any reason, large scale cleaning is felt to be necessary, it is wise first to seek the advice of a local lichenologist or contact the Churchyard Co-ordinator of The British Lichen Society (see below). Ideally, tombstones should remain in situ. Some lichens are susceptible to the smallest of changes and, when stones have to be repositioned, they are more likely to survive if the stone's alignment remains the same. This applies equally to stones in boundary walls. Headstones propped against these walls inevitably lose many of their lichens and shade out part of the wall flora as well. If a large number of older gravestones have to be moved, perhaps to make way for a church extension, it would again be helpful to ask the British Lichen Society to conduct a survey first. When new headstones are erected, local limestones and sandstones, if available, not only fit more naturally into the surrounding landscape but are also much more conducive to lichen growth than their imported, often highly polished counterparts. Periodically, extensive repairs to the structure of the church itself may be necessary. The walls and towers of medieval churches can be especially rich in rare species and repointing needs to be carried out carefully with soft lime mortar, great pains being take to avoid damage to the lichens themselves. It helps if only a small section of wall is repaired at any one time. One lichenologist described lichen colonies as 'minute, self-maintaining gardens that provide a natural cladding for the stone'. They are beautiful, endlessly fascinating, especially when viewed through a hand-lens. Stone denuded of them looks cold and impersonal. Like those of us who come to churchyards for many and varied reasons, they thrive best in a stable, undisturbed and healthy environment. If we care for these places of rest and spiritual refreshment, we will show both respect for death and reverence for life in all its forms. Please help by allowing the lichens to rest in peace.

The Society is actively involved in conservation. A survey of all the ancient churchyard sites is being conducted and, where possible, recorders should make contact with the minister or church council. Similar surveys are being carried out in woodlands, coastal areas and other habitats. The Lichenologist, an international scientific journal, is published bi-monthly and a popular Bulletin twice yearly. Details of membership are on this site or are obtainable from the Secretary, and queries on conservation matters should be addressed to the Churchyards Co-ordinator, both c/o Botany Department, Natural History Museum, Cromwell Road, London SW7 5BD.

Dobson Frank S. Lichens. An Illustrated Guide to the British and Irish Species. Richmond Publishing. 3rd enlarged edition 1992.

Laundon Jack R. Lichens. Shire Natural History No. 10, 1986.

This article was published as part of the Living Churchyard Project and is obtainable (with line illustrations), free of charge, from the British Lichen Society.

Our grateful thanks to [English Nature] for financial assistance in producing the original leaflet; also to Frank Brightman and Jack Laundon whose pamphlet 'Lichens in Churchyards' (1984) was the precursor to this one, to Dr Vanessa Winchester for the apt description quoted above and to other colleagues for their wise counselling.