Lichenological studies in western North America have lagged behind those of eastern North America and Europe. Several manuals, now mainly outdated, are available for the western United States; no descriptions or keys have ever been compiled for the British Columbia lichen flora. This flora of the Coastal Douglas-fir Dry Subzone in British Columbia, Canada, partially fills this void. The Coastal Douglas-fir Dry Subzone is a small area in the southwestern portion of the province composed of a narrow strip on the eastern side of Vancouver Island and the adjacent Gulf Islands in the Strait of Georgia. It is a unique area in the province with a Mediterranean-type climate. It also has a large and increasing human population. Most of the subzone has been logged once although second growth forests now cover much of the region not utilized by the human population. The lichen flora is based primarily on 5,500 specimens collected for this study. In addition, someminor herbarium collections, including later collections of John Macoun, are also included. A total of 448 species in 114 genera, including 26 species from adjacent zones are treated. Keys and concise descriptions are provided plus information on substratum preferences, abundance within the subzone, and taxonomic problems. Spore diagrams are supplied for many of the crustose genera, especially those with septate or muriform spores. One species new to science already has been published, Gyalideopsis aim'col a Noble & Vezda, and several others are to be described in future publications. One new combination has already been made, Catillaria columbiana (Merr.) Noble, and two others, Lecanora ochrococca (Nyl.) Noble and Arthothelium macounii (Merr.) Noble, will be published in a forthcoming checklist of the province. Lecanora phaeobaea Tuck, has proved to be synonymous with Lecanora ochroccoca, and Solenospora hassei (Zahlbr.) Zahlbr. with Lecania dudleyi Herre. Ninety-six species new to British Columbia were encountered, primarily among the microlichens. Ten genera were added to the provincial checklist. A first assessment of many taxonomic problems was made and others noted. Type specimens of many poorly known California species were examined for confirmation of identification- of the local collections. Some difficult genera require monographic treatment before the local flora can be treated any more than tentatively. Local distributions within the subzone are discussed. Eight patterns are distinguished reflecting frequency, climate constraints, substratum restrictions, and human influences. Oceanic distributions make up several distinctive patterns including marine oceanic, strictly oceanic (non-marine) and hyperoceanic. An analysis of the world distributions of the species composing the local flora showed that the majority are very widespread with an essentially continuous range. Twelve different elements are recognized. Important elements include the circumboreal element (31%), the western North American endemic element (18%), the circumtemperate element (12%), the western North America-Europe disjunct element (11%), and the western North America-eastern North America-Europe disjunct element (8%). Eastern Asia, despite its relative proximity, has only minor affinities with the local flora. This study is a preliminary flora of the lichens of the Coastal Douglas-fir Dry Subzone. It provides a manual to encourage others to look at these poorly known cryptogams; it also acts as the foundation for future work. / Science, Faculty of / Botany, Department of / Graduate