Skip to content
1927 Map of the Arboretum

Herbarium of the Arnold Arboretum (A)

Established in 1872, the Herbarium of the Arnold Arboretum (A) contains approximately 1.5 million specimens housed in repositories across Harvard University. While the bulk of these collections reside on the main campus in Cambridge, Massachusetts, the Herbarium of Cultivated Plants (including spontaneous flora) and Seed Herbarium are curated at The Arnold Arboretum in Jamaica Plain, Massachusetts. Related campus-wide resources comprise the Harvard University Herbaria and are one of the largest (more than 5 million specimens) university collections in the world; third largest in the United States.

Dried specimens preserve genetic information, provide data on historical flowering and fruiting times, and play a vital role in understanding evolutionary relationships among plants, their geographic distributions, and their economic uses. Herbarium vouchers are routinely gathered to support research and are a necessary component of living collections documentation and worldwide plant expedition initiatives.

Herbarium of Cultivated Plants

The Herbarium of Cultivated Plants is a collection within the Herbarium of the Arnold Arboretum (A). Allied with five additional collections, the resources of the Harvard University Herbaria comprise one of the largest comprehensive collections of algae, bryophytes, fungi, and vascular plants in the world.

As of January 2022, the Herbarium of Cultivated Plants contained 120,681 specimens. Of these, 49,115 specimens document extant and historic accessions while 69,314 non-Arnold Arboretum specimens have been amassed from cultivated sources across North America, Asia, and Europe. Specimens collected from Arboretum accessions are searchable using Plant Search.

The Spontaneous Flora Collection, comprised of 2,252 specimens collected from spontaneous vegetation on the Arboretum grounds, is also housed here.

Management and development of the collection is guided by the Cultivated Herbarium Collections Policy [pdf].


The Herbarium of Cultivated Plants is located in the Hunnewell Building and is open, by appointment, Monday through Friday, 10:00am – 3:00pm. Please contact the Keeper of Living Collections at 617.384.5769 to make an appointment. The herbarium is closed weekends and holidays.

Herbarium of Cultivated Plants Initiatives

Voucher specimens are collected from Arboretum accessions and are added to the herbarium annually. Documenting accessions in flower and fruit, vouchers record the growth, development, and performance of plants in the collections and are essential tools for identity verification. At present, curatorial staff are working to voucher Plant Collections Network holdings. Vouchers are also collected from plants used for scientific study in an ongoing effort to document the research use of the living collections.

Read more about the utility of maintaining specimens of cultivated origin in the Herbarium of Cultivated Plants (formerly the Cultivated Herbarium, Horticultural Herbarium):

  • Kobuski, C.E. 1958. The Horticultural Herbarium. Bulletin of Popular Information vol. 18 no. 5: 25-28. [pdf].
  • Sutton, S.B. 1965. The Herbarium Introduced. Bulletin of Popular Information vol. 25 no. 6: 38-40. [pdf].
  • Primack, D., C. Imbres, R.B. Primack, A.J. Miller-Rushing and P. Del Tredici. 2004. Herbarium specimens demonstrate earlier flowering times in response to warming in Boston. American Journal of Botany 91(8): 1260–1264. [pdf]
  • Dosmann, M. 2007. The Arnold Arboretum’s Living Collections: A Respository for Research. Arnoldia 65(2):30–39. [pdf].

Seed Herbarium

Beginning in the 1960s, Arboretum propagator Al Fordham created a seed herbarium to assist the growing of unfamiliar species. Collecting the seed of several hundred rare and unusual taxa, Fordham envisioned a unique resource for the identification and propagation of woody plants from around the world. Carrying forward Fordham’s vision, Arboretum greenhouse staff continued to collect, and today maintain a seed herbarium of more than 2,100 samples, of which 662 are sourced from accessioned plants in the living collection.