Have you seen this?
Researchers of plant and life sciences, historical landscape studies, and New England history can now access decades of Arnoldia through the Ecology & Botany II Collection of JSTOR, an online repository with access to thousands of academic journals.
Arnoldia is the quarterly magazine published by the Arnold Arboretum since 1941. From 1912 to 1940, it was published as the Bulletin of Popular Information, in order to keep the public informed of horticultural developments and highlights at The Arnold Arboretum. The Bulletin is also available through JSTOR. This additional point of access to our institutional history is an exciting development!
JSTOR may require a subscription through your academic institution. The staff at the Arnold Arboretum Horticultural Library can gladly assist your research needs.