Ancient Trees in the Hortus Botanicus

The tulip tree by professor Herman Boerhaave's name came from a Virginia seed a London apothecary posted across the Channel in October 1716, eleven days before it reached Leiden's soil. The zelkovas came further: Philipp Franz von Siebold, a physician stationed on the Dutch trading post at Deshima in the 1820s, sent home more Japanese plants than any European before him, and the Hortus holds the first zelkovas that ever left the country. A ginkgo planted in 1785 spent a century and a half producing nothing but the small catkins of a male tree, until gardeners grafted female branches onto it in 1935 so it would finally bear seed. A date-plum, which children call the Halloween tree, has holes in its trunk left by a maple that seeded itself inside the older tree's wood in the late 19th century. A horse chestnut at the garden's edge is the thickest of its kind recorded anywhere in the Netherlands, 5.8 metres round by the national monumental tree register's own measurement, its roots reaching almost to the water of the Witte Singel. And a catalpa leaning toward the canal is kept from going in by cables tied to another tree on this same list. The garden is open to the public with an admission charge.