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1927 Map of the Arboretum


Charles Sprague Sargent inaugurated the Arboretum’s program for plant exploration.
Portrait of Charles Sprague Sargent


Expeditions Unveiled is an ongoing effort to define, inventory, and summarize the Arboretum’s history of plant exploration. The project initially developed in 2014 from a simple question we were unable to answer: How many expeditions have been mounted by and with the Arnold Arboretum? Please pardon our appearance as we work to update our list of expeditions. Read more about the goals and methods of the 2014 Expeditions Unveiled project.


  • 56 expeditions in the United States
  • 22 expeditions to China
  • 8 expeditions to Japan
  • 173 expeditions total

Fun Facts

  • An expedition is a collection event sponsored by the Arboretum and carried out by Arboretum staff, with planned objective(s) to collect living or preserved plant specimens. In some instances, a collection event may not have been formally sponsored by the Arboretum, but resulted in significant contributions to the collections (living or preserved); it is included as a non-Arnold Arboretum expedition.

  • A campaign is a collection event with more than one discrete start and end date, yet with objective(s) (e.g., location or taxa) that remained consistent over time.



  • A contract is a collection event where the Arnold Arboretum sponsored and determined or agreed to the objective(s), but Arboretum staff did not participate.


Arboretum expeditions
non-Arboretum expeditions
countries and territories visited


  • 2010's

  • 2000's

  • 1990's

  • 1980's

  • 1970's

  • 1960's

  • 1950's

  • 1940's

  • 1930's

  • 1920's

  • 1910's

  • 1900's

  • 1890's

  • 1880's

  • 1870's