The Voynich manuscript is a mysterious, undeciphered, illustrated book thought to have been written in the 15th or 16th century. The author, script, and language of the manuscript remain unknown. Even the illustrations are mysterious:
The first section of the book is almost certainly herbal, but attempts to identify the plants, either with actual specimens or with the stylized drawings of contemporary herbals, have largely failed. Only a couple of plants (including a wild pansy and the maidenhair fern) can be identified with some certainty. Those “herbal” pictures that match “pharmacological” sketches appear to be “clean copies” of these, except that missing parts were completed with improbable-looking details. In fact, many of the plants seem to be composite: the roots of one species have been fastened to the leaves of another, with flowers from a third.
It’s all quite obvious to xkcd though.