The most important tree in the garden - the chocolate giving tree.

Botanic Garden Audio trail

14. The cocoa tree

The celebrated author shares his passion for the Botanic Garden and reads from the end of the His Dark Materials trilogy.

The plant growing on the island in the lower garden pond.

The new Merton borders - the latest Botanic Garden experiment.

A cactus and a euphorbia - an example of convergent evolution.

The rainforest and the desert in the middle of the city of Oxford.

A pink flowered plant that provides a life-saving anti-cancer drug.

Lili talks about the water lilies she looks after every day.

An audio tour of the Botanic Garden, University of Oxford, told by its gardeners and author Philip Pullman.