Our Collections

BTA holds collections of plants from the deserts of the United States, Mexico, Australia, Madagascar, India, China, Japan, Israel, South America, the Middle East, Africa, the Mediterranean, and the Arabian Peninsula.

Among these are three Nationally Accredited Plant Collections*: eucalyptus trees, desert legumes, and southwest oaks. To become nationally accredited by the Plant Collections Network, Boyce Thompson Arboretum has to demonstrate “long-term institutional commitment to collect, document, grow, and maintain living plants of a defined plant collection and conserve its germplasm.”

Eucalyptus Collection

BTA’s Eucalyptus collection was accredited in 2018. At 93 taxa, it is one of the largest collections in the US and features many trees planted in the 1920s, including “Mr. Big,” a Champion Tree. Native to Australia and Tasmania, the genus has over seven hundred species of flowering trees and shrubs. Eucalyptus trees are the preferred habitat and forage for koalas.

Oak Collection

In 2012, BTA gained accreditation of its collection of oak trees (genus Quercus). With an estimated 500 naturally occurring taxa distributed throughout a broad variety of climate zones and habitats, the genus is virtually impossible to represent at any single garden. Today, 20 gardens with large oak collections participate in this multi-site collection. BTA’s collection includes oak trees sourced from Arizona, New Mexico, and west Texas in the US, and Sonora, Chihuahua, and Coahuila in Mexico.

Desert Legume Collection

BTA’s Desert Legume (or Fabaceae Collection) is the first primarily seed-based collection accredited (2014) by Plant Collections Network. The internationally recognized seed bank of 1,454 taxa is housed at the University of Arizona in Tucson, while 206 taxa are grown in field plantings and the Taylor Family Desert Legume Garden at the Arboretum.

* The American Public Gardens Association Plant Collections Network coordinates a continent-wide approach to plant germplasm preservation, and promotes excellence in plant collections management. Plant Collections Network is a long-term collaboration between the American Public Gardens Association and the USDA–Agricultural Research Service. Gardens and arboreta must maintain collections according to professional standards; provide reasonable access to collections for research, evaluation, and introduction; and demonstrate the likelihood for long term stability and support for collection.

BTA holds collections of plants from the deserts of the United States, Mexico, Australia, Madagascar, India, China, Japan, Israel, South America, the Middle East, Africa, the Mediterranean, and the Arabian Peninsula.

Eucalyptus Collection

Oak Collection

Desert Legume Collection

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