Fisher, P.J. & Proctor. M.C.F. (1978) Observations on a season's growth in Parmelia caperata and P. sulcata in South Devon. Lichenologist 10:81-89. Hawksworth. D.L. (1974) The lichen flora of Derbyshire - Supplement I. Naturalist 1974: 57-64. Hawksworth. D.L. & McManus, P.M. (1989) Lichen recolonization in London under conditions of rapidly falling sulphur dioxide levels, and the concept of zone skipping. Botanical Journal of the Linnean Society 100: 99-109. Hawksworth, D.L. & Rose, F. (1970) Qualitative scale for estimating sulphur dioxide air pollution in England and Wales using epiphytic lichens. Nature 227: 145-148. Hawksworth, D.L., Rose, F. & Coppins, B.J. (1973) Changes in the lichen flora of England and Wales attributable to pollution of the air by sulphur dioxide. In Air Pollution and Lichens (B.W. Ferry, M.S. Baddeley & D.L. Hawksworth, eds): 330-367. London: Athlone Press of the University of London. Laundon. J.R. (1967) A study of the lichen flora of London. Lichenologist 3: 277-327. Laundon, J.R. (1970) London's lichens. London Naturalist 49: 20-69. Paulson, R. (1918) Notes on the ecology of lichens, with special reference to Epping Forest. Essex Naturalist XVIII'. 276-286. Paulson, R. & Thompson. P.G (1911) Report on the lichens of Epping Forest (First paper). Essex Naturalist XVI: 136-145. Paulson. R. & Thompson. P.O. (1913) Report on the lichens of Epping Forest (Second paper). Essex Naturalist XVII: 90-105. Paulson, R. & Thompson, P.G. (1919) Supplemental report on the lichens of Epping Forest. Essex Naturalist XIX: 27-30. Purvis, O.W.. Coppins. B.J., Hawksworth. D.L., James, PW. & Moore, D.M. (1992) The Lichen Flora of Great Britain and Ireland. In press. London: The Natural History Museum. Rose, C.I. &. Hawksworth. D.L. (1981) Lichen recolonization in London's cleaner air. Nature 289: 289-292. Sowter. F.A. & Hawksworth. D.L. (1970) Leicestershire and Rutland Cryptogamic notes, I. Transactions of the Leicester Literary and Philosophical Society 64: 89-100. Turner, D. & Dillwyn, L.W. (1805) The Botanist's Guide through England and Hales. 2 vols. London: Phillips & Fardon. Warren Spring Laboratory (1969-88) U.K. Smoke and Sulphur Dioxide Monitoring Networks. Summary Tables. Stevenage: Department of Trade and Industry. Appendix 1: Checklist Of Lichens Recorded On Trees And Wood In Epping Forest 1784-1991 Notes: Species in bold type were seen in 1989-91. Species in italic type were not seen in 1989-91. Species not found in 1968-70 present in 1989-91 are indicated by an asterisk (*). Nomenclature follows Purvis et al. (1992). The names of collectors who last recorded a species not seen in 1989-91 are indicated by their surnames. 1MI = International Mycological Institute. E = Royal Botanic Garden Edinburgh. STD = Southend-on-Sea Museum Acrocordia gemmata (Ach.) Massal.: Paulson & Thompson. Anaptychia ciliaris (L.) Korber: Forster. Anisomeridium biforme (Borrer) R.C. Harris: Crombie. Arthonia cinnabarina (DC.) Wallr.: Crombie. A. radiata (Pers.) Ach.: Crombie A. spadicea Leighton: Rose. Arthopyrenia punctiformis Massal.: Forster. Bacidia rubella (Hoffm.) Massal.: Crombie. Biatora sphaeroides (Dickson) Korber: Forster. Buellia punctata (Hoffm.) Massal.: Pentecost. Calicium abietinum Pers.: Paulson & Thompson. This record could well have referred to C. glaucellum Ach. C. quercinum Pers.: Paulson & Thompson. C salicinum Pers.: Rose. C. viride Pers. (*): On Quercus, on a single tree. Wintry Wood. The last previous report was by Crombie. Caloplaca flavorubescens (Huds.) Laundon: Crombie. C ferruginea (Huds.) Th.Fr.: Forster. C. luteoalba (Turner) Th.Fr.: Crombie. Candelaria concolor (Dickson) B.Stein(*): On Salix, a single specimen (thallus K-), Higham Park Lake (IMI 348256). The last previous report was by Crombie. Candelariella vitellina (Ach.) Mull. Arg.: Paulson & Thompson. C. xanthostigma (Ach.) Lettau: Forster. Chaenotheca chrysocephala (Turner ex Ach.) Th.Fr.: Crombie. C. ferruginea (Turner ex Ach.) Migula: On dry bark of Quercus, locally abundant: Dulsmead Hollow, Epping Thicks. King's Oak, and Wintry Wood. C furfuracea (L.) Tibell: Paulson & Thompson. Chrysothrix candelaris (L.) Laundon: Forster. Cladonia caespiticia (Pers.) Florke: Crombie. C chlorophaea (Florke ex Sommerf.) Sprengel: Rose: on large Quercus root, Court Hill, 1983, Skinner: on rotten log. High Beach, 1983, Skinner. C. coccifera (L.) Willd. (*): On decaying Fagus stump. Oak Hill. C. coniocraea auct.: Common on bark of a wide range of trees, especially in damper situations and on stumps. C crispata var. cetrariiformis (Delist*) Vainio: On rotting stump. Copley Plain, 1985, Adams (STD). C. digitata (L.) Hoffm. (*): On tree stump. Court Hill, 1983, Skinner: on base of old Fagus and Quercus, Epping Thicks, and Wintry Wood. 97