Brown, who is now at work on a field guide to the orchids of the Northwest, begins this definitive guide to orchids of the Northeast with a chapter on where and when to find these captivating flowers. He continues with information on identifying the various genera and follows with a list--in alphabetical order--of 71 orchid species and varieties, with a drawing of each, along with data on 50 hybrids. Each listing contains a detailed description of the orchid, its habitat, blooming dates, measurements, and abundance (rare to frequent), and a map showing where the species can be found. There are 192 lavish color photographs, 94 black-and-white drawings by Stan Folsom, a state-by-state checklist, and a glossary. George Cohen