The Botanical Garden hosts incredibly old plants, usually called "historic trees". Like all the plants in the Garden, they are labelled with the scientific name (Latin binomial) of the species, the initials of the scholar who first denominated and described them correctly, their family and place of origin and, in this case, also the year they were planted in the Garden.
The Hortus sphaericus has a Mediterranean palm (Chamaerops humilis L.) which, at present, is the oldest plant in the Garden, as it was planted in 1585 and made famous by Goethe who dedicated to it some of his essays and scientific works. There is also a ginkgo (Ginkgo biloba L.) dated 1750, and a southern magnolia (Magnolia grandiflora L.) which was probably planted in 1786 and is considered to be the oldest in Europe.
Other historic trees grow in the Arboretum (outside the circular wall), which was designed in the second half of the 18th century, particularly by the Prefects Giovanni Marsili and Roberto de Visiani. This area also contains an artificial hillock ("Montagnola" or Belvedere) with winding paths recalling romantic English-style parks. Here is a gigantic hollow-trunked Oriental plane (Platanus orientalis L.) (1680) and a Himalayan cedar (Cedrus deodara (D.Don) G.Don fil.), not as old as the previous tree and therefore not yet historic, but nevertheless important, as it was the first specimen of this species to be introduced into Italy (1828).