- Royal Botanic Gardens, Kew
- 16,900 total number
- United Kingdom (Richmond)
Formally established in 1759, Royal Botanic Gardens, Kew (UK) located in Richmond, London, UK, had 16,900 unique plant species in cultivation as of May 2019, making it the most diverse collection of living flora at a single-site botanic garden. If also including subspecies and cultivars, that figure increases to 21,843 taxa. This is based on self-reported data from GardenSearch, a global database of more than 3,700 botanical institutions that is vetted and maintained by Botanic Gardens Conservation International.
According to the same dataset, the next two largest living collections at single-site gardens were 13,950 and 13,415, respectively.
Kew Gardens is currently undergoing a stock-take of all its collections and expects its number of species and taxa to rise significantly when completed in 2021/22. Beyond its living collections, RBG, Kew is also custodian to one of the most extensive archives of preserved vascular plants (c. 7 million specimens) and dried fungi (c. 1.25 million specimens) in its Herbarium and Fungarium, respectively.
Also managed by RBG, Kew, the Millennium Seed Bank – based at Kew’s satellite Wakehurst facility in West Sussex – contains more than 2.4 billion seeds from almost 40,000 species, making it the world’s largest seed repository.
There are larger living collections if multi-site botanic gardens are factored in, or if cultivars and sub-specific taxa are included, but this record focuses exclusively on the total plant species being grown at a single facility.