Vascular Plants of the Pacific Northwest, in five parts, offers the first complete guide, with keys, to the ferns, fern-related, and seed-bearing plants of Washington, northern Oregon, Idaho north of the Snake River plains, the mountainous western part of Montana, and southern British Columbia. Each volume gives complete regional synonymy, type collections, geographic ranges, ?genuine? common names, and chromosome numbers for each species, as well as economic importance and horticultural features. Part 4 covers the families of plants, other than sunflowers, that have united petals. Since this volume includes many of the plants most useful as ornamentals, gardeners, both amateur and professional, will be interested in the comments concerning species suitable for cultivation in rockery, woodland, and moist or general garden areas. Illustrated by Jeanne R. Janish.