Reflecting the fact that horticulture has become a global industry, an Australian publisher recently teamed up with regional publishers in Canada, the United States, and other countries to produce the most comprehensive pictorial encyclopedia of plants from around the world. Flora: A Gardener's Encyclopedia (Timber Press, Portland, 2003; $100; www.timberpress.com or 800/327-5680), a 1,584-page two-volume set, lists more than 20,000 plants and is copiously illustrated with more than 12,000 color photographs.

Flora benefits from the input of its chief consultant, Sean Hogan, a Portland-based horticulturist who brought his expertise to bear on the plant listings, which include a strong selection of Western natives.

The first edition of Flora comes with a CD-ROM that lets you search for plants by USDA hardiness zone, height, uses, exposure, flower color, and bloom season.