In 1587 the young University of Leiden asked for permission from the mayor of Leiden to establish a hortus academicus behind the university building, for the benefit of the medical students. The request was granted in 1590, and the famous botanistCarolus Clusius was appointed as prefect. Clusius arrived in Leiden in 1593. His knowledge, reputation, and international contacts allowed him to set up a very extensive plant collection. Clusius also urged the Dutch East India Company to collect plants and plant specimens in the colonies. The original garden set up by Clusius was small, but contained more than 1000 different plants. The collecting of tropical and sub-tropical plants was continued under Clusius' successors. Especially Herman Boerhaave, contributed greatly to the fame of the Hortus with his efforts to collect new plants and specimens, and with his publications, such as a catalog of the plants then to be found in the Hortus. Another major contribution to the collections was made by Philipp Franz von Siebold, a German physician who was employed on Deshima by the VOC from 1823 until his expulsion by Japan in 1829. During that period he collected many dried and living plants from all over Japan, and sent them to Leiden. The first greenhouses appeared in the Hortus in the second half of the 17th century, the monumental Orangery was built between 1740 and 1744. From its original plan the Hortus was expanded in 1736 by Adriaan van Royen and Carl Linnaeus, and in 1817 by Theodor Friedrich Ludwig Nees von Esenbeck and Sebald Justinus Brugmans. In 1857, a part was used for building the new Leiden Observatory.
Collection
From a historical perspective, the old Tuliptree from 1716, Date plum from 1739, Ginkgo from 1785 and Golden Chain from 1725 to 1818, are worth mentioning. The greenhouses with Victoria amazonica and other tropical plants, and the large collection of sub-tropical plants in the recently renovated Orangery and the new Winter Garden draw many visitors. The park itself is an oasis inside the old city, with many more interesting plants and trees. A Japanese garden in honour of Von Siebold opened in 1990. A reconstruction of Clusius' original garden, based on a plant list dating from the end of the 16th century, was opened in 2009. From a scientific point of view, the Leiden Hortus is known for its collections of Asian Araceae, Hoya, Dischidia, Nepenthes, ferns and one of the biggest collections of Asian orchids in the world.
