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1927 Map of the Arboretum

Collection Statistics

Curatorial Fellows Joyce Chery and Jordan Wood verify Amelanchier nantucketensis accessions. Kyle Port
Curatorial Fellows Joyce Chery and Jordan Wood verify Amelanchier nantucketensis accessions

Permanent Collections

As of January 2024, the permanent collections (which exclude nursery holdings) comprise 15,953 individual plants that belong to 10,401 accessions. These accessions represent 2,091 different species and 1,383 cultivars, which respectively illustrate the Arboretum’s broad biological and horticultural diversity, exceptional for a temperate woody plant collection.

The collections are considered one of the best documented in the world, especially with regard to wild provenance. Many of these lineages are of historical and botanical importance, representing the original North American introductions of eastern Asian plants collected by Arboretum staff such as Charles Sprague Sargent, Ernest H. Wilson, John G. Jack, Joseph Rock, and William Purdom.

Contemporary explorers continue a legacy of plant discovery now guided by the Campaign for the Living Collections.

Read more about the over 150 years’ of plant exploration at the Arnold Arboretum.


Table 1. Taxonomic profile of the Living Collections (Includes Nursery Holdings) of the Arnold Arboretum.a

RANKNUMBER
Families117
Genera416
Species2,173
  Subspecies103
  Varieties328
  Formae60
  Cultivars1,403
Interspecific Hybrids429
Intergeneric Hybrids14
aNumbers for infraspecific ranks correspond only to those accessions where rank is known.

Table 2. Provenance of Accessions in the Living Collections (Includes Nursery Holdings) of the Arnold Arboretum.

PROVENANCETOTAL NUMBERPERCENT OF TOTAL
Wild
  Direct3,26130
  Indirecta9649
Garden2,94627
Uncertainb3,68834
aFrom a cultivated plant of known (indirect) wild origin.
bIncludes 2,574 existing or spontaneous accessions whose provenance cannot be determined.

Dead Collections

Only a minority of the accessions ever attempted to be grown in the collections of the Arnold Arboretum are currently alive—some perished on the grounds, while others representing propagules (e.g., seed, graft, cutting) may have never grown to maturity. The records associated with these legacy collections hold immense value in documenting the history of plant introductions, since the Arboretum facilitated the initial point of entry in North America for many species.

As of January 2024, the legacy collections comprised 99,533 accessions representing 22,266 taxa (kinds). Of these, 69,774 individual plants belonging to 46,177 accessions representing 13,550 taxa (kinds) were inventoried within the living collections (which include nursery holdings) before perishing.


Table 3. Taxonomic profile of the Legacy (Dead) Collections of the Arnold Arboretum.a

RANKNUMBER
Families 261
Genera 1,612
Species 12,186
  Subspecies 332
  Varieties1,705
  Formae 313
  Cultivars 8,820
Interspecific Hybrids 1,698
Intergeneric Hybrids 102
aNumbers for infraspecific ranks correspond only to those accessions where rank is known.

Table 4. Provenance of the Legacy (Dead) Accessions of the Arnold Arboretum.

PROVENANCETOTAL NUMBERPERCENT OF TOTAL
Wild
  Direct 18,313 18
  Indirecta 5,629 6
Garden 32,226 32
Uncertainb 43,365 44
aFrom a cultivated plant of known (indirect) wild origin.
bIncludes 1,663 existing or spontaneous accessions whose provenance cannot be determined.