Arboretum Quick Facts

  • “Arboretum” means living museum, where trees, shrubs, and vines (woody plants) are grown for science, education, and enjoyment
  • Over 281 acres
  • Established 1872 with a bequest from James Arnold and land donated by Benjamin Bussey
  • A National Historic Landmark
  • Land was donated by Harvard College to the City of Boston in 1882, then leased back to Harvard for 1,000 years for $1 a year
  • Part of Boston’s Emerald Necklace
  • Arboretum scientists travel the globe to study and collect plants

What is an accession?

There are over 16,000 accessioned plants at the Arboretum. An accessioned plant is one that is part of the Arboretum’s official collections. It has a unique identifying number, and careful records are kept about the plant, including its name, age, who collected it, and where it came from.


Much of this information is printed on plant labels, which can be found on branches, tree trunks, and stakes throughout the landscape.

Plant labels show:

  • Accession number
  • Plant family
  • Scientific name
  • Accession date
  • Source/collection data (where the Arboretum got the plant) (G signifies garden origin; W signifies wild origin; U signifies uncertain origin; Z signifies garden plant of known wild origin)
  • Name and institution of plant collector, if known
  • Common name
  • Location within the Arboretum
  • Propagation material (the plant’s stage when it arrived at the Arboretum) (SD signifies seed; SC signifies scion; PT signifies plant; GR signifies graft; DV signifies division; SG signifies seedling)