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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 July 2021, the permanent collections (which exclude nursery holdings) comprise 15,720 individual plants that belong to 10,371 accessions. These accessions represent 2,077 different species and 1,399 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 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
Families111
Genera397
Species2,173
  Subspecies102
  Varieties334
  Formae63
  Cultivars1,415
Interspecific Hybrids433
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
  Direct3,25030
  Indirecta9108
Garden2,94627
Uncertainb3,82535
aFrom a cultivated plant of known (indirect) wild origin.
bIncludes 2,635 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 July 2021, the legacy collections comprised 85,190 accessions representing 20,268 taxa (kinds). Of these, 68,277 individual plants belonging to 45,482 accessions representing 13,446 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 232
Genera 1,427
Species 11,168
  Subspecies 315
  Varieties1,595
  Formae 306
  Cultivars 7,970
Interspecific Hybrids 1,605
Intergeneric Hybrids 101
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 15,788 18
  Indirecta 4,669 6
Garden 26,518 31
Uncertainb 38,215 45
aFrom a cultivated plant of known (indirect) wild origin.
bIncludes 1,549 existing or spontaneous accessions whose provenance cannot be determined.