This grove of London plane-trees dates back to the 1920s. These trees are hybrids of the American sycamores and Oriental plane-trees. The natural structure of their sturdy trunks and leafy canopy is echoed in the architectural design of the nearby West Conservatory. Longwood's trees represent its oldest plant collection, with some dating back to 1798, when the Peirce family began planting trees on the land. Many of those original trees can still be found in Peirce's Park.