The major works on British lichens published between 1724 and 1780 are briefly reviewed. The new lichens published in Withering's Botanical Arrangement of 1776 have been mostly overlooked; they were based on species described by Dillenius. These lichens are typified here, along with Withering's new lichens published in later editions of the Arrangement. Altogether 41 species are reviewed. The following 16 new combinations based on Withering's species are presented, with synonyms in parenthesis: Anaptychia runcinata (A.fusca), Caloplaca crenularia (C. festiva), Qadonia humilis (C. conista, C. conistea, C. conoidea), Qadoniapeziziformis (C. capitata), Cladonia ramulosa (C. anomaea, C. pityrea), Collema auriforme (C. auriculatum), Collema dichotomum (C. fluviatile), Collema fuscovirens (C. tuniforme), Dermatocarpon luridum (D. aqualicum, D. weberi), Leptogium gelatinosum (L. sinuatum), Lobaria virens (L. laetevirens), Peltigera didactyla (P. spuria), Peltigera lactucifolia (P. hymenina), Physconia distorta (P. pulverulacea), Ramalina lacera (if. duriaei), and Tornabea scutellifera (T. atlantica).
Later names affected by Withering's taxa are also investigated, and 12 are shown to be nomenclaturally superfluous. Other names are later homonyms, with the result that seven species require change of author citation as follows: Dactylina madreporiformis (Ach.) Tuck., Lecanora crenulata Hook., Psora lurida (Ach.) DC, Ramalina polymorpha (Liljeblad) Ach., Solorina spongiosa (Ach.) Anzi, Stereocaulon ramulosum Rauschel, and Sticta fuliginosa (Hoffm.) Ach.
The nomenclatures and systematic position of Cladonia conista C. Robb. ex Allen nom. illeg., Cliostomum griffuhii (Sm.) Coppins, Leptogium palmatum Mont., Lichen squamatus Dickson, Pachyphiale cornea (Ach.) Poetsch, and Pycnothelia papillaria Dufour is discussed, the correct name for Leptogium palmatum being L. corniculatum (Hoffm.) Minks and for Pachyphiale cornea being P. carneola (Ach.) Arnold. A history and account of Withering's herbarium is included.