Arnold Arboretum of Harvard University
www.arboretum.harvard.edu/
John Root’s Butterflies of the Northeast
http://www.johnroot.net/butterfly.html
Massachusetts Horticultural Society
http://www.masshort.org/
New England Wildflower Society
http://www.newfs.org
North American Butterfly Association
http://www.naba.org/
Northeast Organic Farming Association (NOFA), MA Chapter
http://www.nofamass.org/
Tower Hill Botanic Garden
http://www.towerhillbg.org/
UConn Plant Database of Trees, Shrubs and Vines
http://www.hort.uconn.edu/Plants/index.html
UMass Extension
http://www.umassextension.org/
Weston Nurseries
http://www.westonnurseries.com/