In 18th century Germany, where modern forestry began, a curious sort of library began to grow.

Enthusiasts began to collect samples of different woods, but instead of simple blocks the samples were fashioned in the shape of books. These wooden “books” could be opened to reveal a hollowed out compartment where botanical samples of the source tree were stored—leaves, seeds, nut, twigs, fruit, flowers, pieces of root and bark. In some cases, written descriptions of the tree and the diseases it might suffer from were also included. The “books” were arranged in shelves, just like in a regular library, with the spine showing where the labels were attached.

A xylotheque at Stift Lilienfeld in Austria. Every “book” is made by the wood of the tree that is documented inside. Photo credit: Haeferl/Wikimedia