THE LICHENS OF LAWNSWOOD CEMETERY, NORTH LEEDS
M. R. D. Seaward
Dept. of Archaeological. Geographical & Environmental Sciences, University of Bradford,
Bradford BD7 1DP
Although Lawnswood Cemetery (grid. ref. 44/26.39 & 44/26.38; alt. 140-155 m) is distinctly suburban, being mainly situated in an area of reasonably dense housing and adjacent to a major highway (A660), the lichen flora is relatively rich compared with that of its environs. This is due in part to the wide range of habitats and substrata afforded to the cemetery lichens, with a variety of imported calcareous and siliceous stones, as well as many different trees and shrubs of varying ages. However, it should be noted that the younger trees often support a richer epiphytic lichen flora since the older trees have an artificially induced acidic bark generated by air pollution in the 19th and 20th centuries which is not favourable for most lichens; although this has dramatically reduced in recent decades, the low pH of the bark on trees that would naturally have a higher pH has persisted. The influence of nutrient enrichment (mainly nitrogen compounds) on corticolous (bark), lignicolous (timber) and saxicolous (stone) substrata brought about by the locally-derived, and indeed long-distance, dispersal of agrochemicals is also evident. A further factor which encourages and maintains the relatively high diversity of lichens at Lawnswood is the sacred nature of the location, its integrity being paramount in the conservation of these and other biota. Much of this is due to the vigilance of those who are responsible for its upkeep and to the Friends of Lawnswood Cemetery.
A preliminary checklist of 86 lichen species is provided below, together with basic information on their preferred substrata and distribution within the cemetery (N = northern part 44/26.39; S = southern part 44/26.38).
Memorials, walls & buildings:
(a) Siliceous
Acarospora fuscata N,S
Baeomyces rufus N
Buellia aethalea N,S
Candelariella vitellina N,S
Lecanora conizaeoides N,S
L. polytropa N
L. soralifera N
Lecidea grisella S
Lecidella carpathica S
L. scabra N,S
Lepraria incana s.lat. N,S
Melanelixia fuliginosa S
Porpidia crustulata N,S
P. soredizodes N,S
P. tuberculosa N,S
Psilolechia lucida S
Rhizocarpon distinctum S
R. reductum S
Trapelia coarctata N,S
T. glebulosa S
T. placodioides N,S
(b) Calcareous
Aspicilia calcarea N,S
- contorta N,S
Caloplaca citrina s.str. N,S
C. crenulatella N,S
C. flavescens N,S
C. flavocitrina N,S
C. holocarpa s.str. N,S
C. oasis N
Candelariella aurella N,S
Cladonia fimbriata N
Collema auriforme N.S
C. crispum N,S
Lecanora albescens N,S
L. crenulata N,S
L. dispersa N,S
L. muralis N,S
L. semipallida S
Lecidella stigmatea N,S
Physcia adscendens N,S
Placynthium nigrum S
Protoblastenia rupestris N,S
Rinodina oleae S
Verrucaria baldensis N,S
V. hochstetteri N,S
V. macrostoma f. macrostoma S
V. macrostoma f. furfuracea N,S
V. muralis N,S
V. nigrescens N,S
V. viridula N,S
Xanthoria parietina S
Compacted soil
Collema tenax var. ceranoides S
Wooden seats (lignum)
Evernia prunastri S
Flavoparmelia caperata S
Hypogymnia physodes S
H. tubulosa S
Lecanora conizaeoides N
L. polytropa N
Melanelixia subaurifera S
Parmelia saxatilis S
P. sulcata N,S
Parmotrema perlatum S
Physcia caesia S
Placynthiella icmalea S
Punctelia subrudecta s.s. S
Ramalina farinacea S
Trapeliopsis flexuosa S
T. granulosa S
Usnea subfloridana S
Xanthoria parietina S
Trees (mainly Acer, Fraxinus, Quercus & Salix) & shrubs
Amandinea punctata N,S
Arthonia radiata N,S
Buellia griseovirens S
Candelariella reflexa N,S
Cladonia fimbriata S
Cliostomum griffithii S
Evernia prunastri N
Hypogymnia tubulosa N
Lecanora chlarotera N,S
L. expallens N,S
L. umbrina S
Lecidella elaeochroma S
Lepraria incana s.lat. N,S
L. vouauxii S
Melanelixia glabratula S
M. subaurifera N,S
Mycoblastus fucatus S
Parmelia sulcata N,S
Parmotrema perlatum N
Phaeophyscia orbicularis N,S
Physcia adscendens N,S
P. caesia S
P. tenella N,S
Punctelia borreri S [New to Yorkshire!]
P. jeckeri S
P. subrudecta s.str. S
Ramalina farinacea N,S
Scoliciosporum chlorococcum S
Xanthoria candelaria s.lat. S
X. parietina N,S
X. polycarpa N,S
Acknowledgements
The author is grateful to Dr Volker John who assisted him in the field and to the dedication of the Friends of Lawnswood Cemetery, more particularly Ann Lightman.