Pennsylvania
Bowman's Hill Wildflower Preserve in New Hope, Pa.
Hunt Institute for Botanical Documentation
Indiana County Parks and Trails
Morris Arboretum at the University of Pennsylvania
Pennsylvania Department of Conservation and Natural Resources
Scott Arboretum at Swarthmore College
Western Pennsylvania Conservancy
Outside of Pennsylvania
Chadwick Arboretum and Learning Gardens at Ohio State University
Holden Arboretum-Kirkland, Ohio
Mount Holyoke College Botanical Gardens
The Arboretum at the Barnes Foundation in Philadelphia
The Edith Johnson Carrier Arboretum-James Madison University
The Morton Arboretum-Nichols, Illinois
The Mountain Top Arboretum in Catskills Mountains
The JC Raulston Arboretum-NC State University
Trees and Shrubs of the Campus of Iowa State University
University of Nebraska-Lincoln Botanical Garden and Arboretum
University of Southern Maine Arboretum
Wildflowers and Trees of Western Pennsylvania
Miscellaneous Sites
American Public Gardens Association
Encyclopedia of Plants and Flowers
Internet Directory for Botany: Arboreta and Botanical Gardens
The United States National Arboretum-Washington, D.C.
What Tree Is It?