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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 2022, the permanent collections (which exclude nursery holdings) comprise 15,835 individual plants that belong to 10,397 accessions. These accessions represent 2,087 different species and 1,392 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
Families112
Genera406
Species2,187
  Subspecies104
  Varieties335
  Formae63
  Cultivars1,407
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
  Direct3,27830
  Indirecta9439
Garden2,94727
Uncertainb3,77834
aFrom a cultivated plant of known (indirect) wild origin.
bIncludes 2,622 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 2021, the legacy collections comprised 94,265 accessions representing 21,556 taxa (kinds). Of these, 68,611 individual plants belonging to 45,644 accessions representing 13,467 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 254
Genera 1,562
Species 11,868
  Subspecies 326
  Varieties1,684
  Formae 313
  Cultivars 8,463
Interspecific Hybrids 1,659
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 17,267 18
  Indirecta 5,175 6
Garden 29,907 32
Uncertainb 41,916 44
aFrom a cultivated plant of known (indirect) wild origin.
bIncludes 1,570 existing or spontaneous accessions whose provenance cannot be determined.