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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 December 2020, the permanent collections (which exclude nursery holdings) comprise 15,464 individual plants that belong to 10,295 accessions. These accessions represent 2,046 different species and 1,405 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
Families110
Genera395
Species2,178
  Subspecies103
  Varieties330
  Formae65
  Cultivars1,415
Interspecific Hybrids431
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
  Direct3,25230
  Indirecta9188
Garden2,94727
Uncertainb3,86935
aFrom a cultivated plant of known (indirect) wild origin.
bIncludes 2,657 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 December 2020, the legacy collections comprised 77,146 accessions representing 18,485 taxa (kinds). Of these, 67,577 individual plants belonging to 44,985 accessions representing 13,304 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 222
Genera 1,277
Species 10,336
  Subspecies 297
  Varieties1,525
  Formae 291
  Cultivars 7,110
Interspecific Hybrids 1,537
Intergeneric Hybrids 100
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 14,876 19
  Indirecta 4,393 6
Garden 22,979 30
Uncertainb 34,898 45
aFrom a cultivated plant of known (indirect) wild origin.
bIncludes 1,529 existing or spontaneous accessions whose provenance cannot be determined.