Lichen is everywhere in Heene Cemetery. One sees it on graves, headstones, trees and walls, yet until the autumn of 2023 we had little idea of which lichens we were looking at. They were, with a few exceptions, small and perhaps rather boring blotches, often resembling flattened splatters of pavement chewing gum.
Yet, the species pages of this website displays some very colourful lichen photographs, as shown here:
Photo-grid of lichen types found in Heene Cemetery (using stock images - not taken in Heene Cemetery)
This discrepancy has a simple explanation. In early October, we were lucky to be visited by two of the country’s top lichenologists, Neil Sanderson, the President of the British Lichen Society and Dr. Paul Cannon, the Chair of the society’s Data Committee. Their generosity in giving us their time and expertise resulted in them confirming that there are at least 49 different species of lichen in the cemetery.
Prior to receiving this confirmation, we thought we had identified 3 lichens, but in fact all three of our identifications were wrong! With lichen, knowing exactly what one is looking at is a highly specialised business.
The survey was extremely helpful, especially as each species was accompanied by a note as to on what ‘substrate’ within the cemetery it had been found (such as granite, sandstone, concrete, or which tree trunk or twig), as shown here:
| Substrate | Number of occurrences within the cemetery |
|---|---|
| Acid sandstone | 3 |
| Basic sandstone | 18 |
| Birch (Betula) | 3 |
| Boundary wall (brick/flint) | 1 |
| Coniferous bark | 1 |
| Elm (Ulmus) bark | 1 |
| Elm (Ulmus) twig | 3 |
| Granite | 1 |
| Hawthorn (Crataegus) bark | 1 |
| Hawthorn (Crataegus) twig | 1 |
| Holly (Ilex) | 1 |
| Lime (Tilia) bark | 2 |
| Lime (Tilia) twig | 3 |
| Limestone | 2 |
| Oak (Quercus) twig | 1 |
| Sandstone | 3 |
| Willow (Salix) bark | 4 |
Types of substrate on which lichen were found in Heene Cemetery, October 2023.
Even a cursory glance at the table above suggests that the place where these surveyed lichen were found was unusual. That many of them were found on stone of some kind, is indeed what one would expect for any cemetery.
Even so, we still had no photographs, but we had been advised to use stock images that had been posted with no copyright restrictions. So, except for the 3 lichens previously mentioned, that’s what we’ve done. (For each species record, an image’s author has been duly acknowledged. Interestingly, many of the fine images we ended up using were taken by Paul Cannon himself.) This therefore departs from an objective that we had set: to only show species photographs that had been taken in the cemetery. We now have 46 lichen photographs that show lichens from somewhere else! (As and when we take our own photographs of the cemetery’s lichens, we’ll be adding these to the website.)
The total of 49 species in Heene’s one-acre site is apparently “reasonable . . . for an urban site in a fairly polluted environment”. We’ve been advised that one could expect three times this number for a “good” cemetery, meaning one that is rural, older than Heene (with its inception date of 1873), and less shaded by trees. (Shade retards the growth of most lichen.)
There are seven general forms that lichens take. The majority in the cemetery are of the crustose type, as follows:
| Type of lichen | Number found in the cemetery | |
|---|---|---|
| Crustose | Crust-like which has bonded to part of the substrate | 42 |
| Crustose-placodioid | Crustose with lobes towards the margin | 0 |
| Filamentous | Fine, soft, hair-like mat or filaments | 0 |
| Foliose | Flattened, leaf-like, often large. Thin and papery when dry, swelling when wet. | 4 |
| Fruticose | Shrubby, like miniature seaweed. Attached to the substrate at only one point. | 0 |
| Leprose | Powdery mass | 2 |
| Squamulose | Small, leaf-like scales, often forming mats | 1 |
Forms of lichen, showing the number of each found in Heene Cemetery, October 2023.
You can read a more authoritative account of a single lichen by John Brownbill in this blog post: A Lichen on the Tilley family Gravestone. The close-up photography used there is excellent.
The fungi of the cemetery’s lichens are capturing most of the carbon that is being fixing by their symbionts. As with the cemetery’s mosses, plants and trees, their role in counter-balancing our polluting ways is a continuous process.
Lichens in general
Lichens are a combination of fungi with one or more species of algae and/or cyanobacteria. This is a stable symbiotic association between the fungi and the algae/cyanobacteria. It benefits both partners. Lichens are listed on this website under the fungi category.
Worldwide, there are perhaps 250,000 species of lichen – although at present ‘only’ 28,000 of these have been identified/named. As you can see from our listing of these lichen species, they have Latin names, not English ones. To make things harder, lichens are frequently being renamed as DNA sampling becomes more widely used.
Lichens can be found worldwide, and in nearly all habitats. They are slow growers that can live for centuries.
Written by Rob Tomlinson