Within the Hortus botanicus Leiden, there are almost thirty trees that are over a century old. The oldest tree is the Laburnum (Laburnum anagyroides) to the right of the entrance. This tree can be found on an inventory made by Pieter Pauw in 1601, and has been moved to this location.
The tulip tree to the left of the entrance was planted in the time of Boerhaave, somewhere between 1710 and 1720. The autumn colours of this tree inspired Jan Wolkers’ final painting, which is now in the collection of the Leiden museum De Lakenhal. Near the glasshouses is a date-plum planted somewhere around 1740 on the location of a small arboretum. The glasshouse complex was built in 1938 surrounding one of the Hortus’ most spectacular trees: a Japanese maidenhair tree (Ginkgo biloba) dating back to 1785. It is one of the oldest specimens of the Netherlands; it was thought to be extinct and rediscovered in China. A female branch was grafted onto our male specimen in 1935. Several other impressive plants still remain from the 19th century, when the Hortus botanicus Leiden expanded. A significant portion of these plants were brought to the Hortus by von Siebold from Japan. (See also Von Siebold plants)