Skip to content
1927 Map of the Arboretum

Plant Exploration

Susan Delano McKelvey, a self-taught botanist and research associate of the Arnold Arboretum, examines an impressive specimen of Agave palmeri near Fish Creek, Apache Trail, Arizona in 1929.
Susan McKelvey with Agave palmeri


Since its founding, the Arnold Arboretum has led the way in plant exploration. Our efforts to collect diverse species from around the globe remain central to our mission. Arboretum collectors gather seeds that become the trees and shrubs in our living collections, along with a rich array of documentation, photographs, and herbarium specimens. Our living collections, library and archives, and herbarium are steeped in the work of plant explorers, past and present. Discover their journeys below.


  • 49 expeditions in the United States
  • 24 expeditions to China
  • 10 expeditions to Japan
  • 118 expeditions total

Fun Facts

  • Jackson Dawson, our first propagator, was a master plantsman. During his 43 years at the Arboretum, he raised and distributed throughout the world 450,718 plants and 47,993 packets of seed and received in return from collectors, arboreta, and botanic gardens, 174,200 plants and 27,729 packets of seed. A truly impressive record!

  • During the ten years that plant explorer Ernest Henry Wilson spent on expeditions to East Asia, he collected more than 1,000 unique accessions for the Arnold Arboretum, and he sent back around 2,500 large-format photographs and 16,000 herbarium specimens (not including duplicates sent elsewhere). Today, about 320 plants growing in the Arnold Arboretum landscape bear Wilson’s name as the collector.

  • Stephen Spongberg and Richard Weaver’s 1977 collecting trip to Japan and Korea made 505 collections, representing 327 taxa. Today there are 225 plants or descendants of those plants living on our grounds. We can preserve plants that might be in decline by taking cuttings and repropagating them. The new plants are clones and are genetically identical to the plants from which they were derived.

  • Since 1991, the North America–China Plant Exploration Consortium has brought together plant collectors from Chinese and American botanical institutions for 17 expeditions. At the Arnold Arboretum, these collaborations have amassed more than 700 distinct collections, with about 940 plants living as of 2020.


Arboretum expeditions
non-Arboretum expeditions
countries and territories visited

Expeditions Unveiled

How many plant collecting expeditions have been conducted by the Arnold Arboretum? Before 2014, we were not quite sure. This simple question prompted an Arboretum-wide effort to define, inventory, summarize, and share our history of plant exploration on the web. Expeditions Unveiled is the fruit of our efforts, where we bring our ever-expanding history of plant exploration to our visitors. Explore our past expeditions using the drop-downs below.

Shiu-ying Hu
Shiu-ying Hu, research botanist and collector at the Arnold Arboretum, stands in a field of lilies. Hu was the second Chinese woman to receive a doctoral degree in Botany from Harvard University.
  • 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

Featured Expedition

Related Stories