Wild Orchids of the Northeastern United States: A Field and Study Guide to the Orchids Growing Wild in New England, New York, and Adjacent Pennsylvania and New Jersey
 
Wild Orchids of Florida: With References to the Atlantic And Gulf Coastal Plains
 
Wild Orchids of the Northeast: New England, New York, Pennsylvania, and New Jersey
 
Wild Orchids of the Canadian Maritimes And Northern Great Lakes Region
 
Wild Orchids of the Pacific Northwest And Canadian Rockies
 
Wild Orchids of the Prairies And Great Plains Region of North America
 
Wild Orchids Of The Southeastern United States, North Of Peninsular Florida
 
Wild Orchids of North America, North of Mexico
 
Wild Orchids of Florida: With References to the Gulf and Atlantic Coastal Plain