The book is most significant for its inclusion of diagrams created from the Middle Ages onwards. As the author explains, the field of data visualisation has a surprisingly extensive history, and it is therefore "critical for us to understand this long evolution and not be overly infatuated with work created in the last decade alone". (Sandra Rendgen's Information Graphics and Understanding The World focus primarily on contemporary infographics, though Lima includes numerous recent examples, too.)
The Book Of Trees doesn't succeed in its ambitious attempt "to convey the long, millennial history of information visualization", as it would likely be impossible to produce a comprehensive history of 1,000 years of infographics in a single volume. But it's a fascinating study, and a useful expansion of the first chapter of Lima's earlier book, Visual Complexity. (Edward R Tufte's classic The Visual Display Of Quantitative Information examines the history of charts, tables, and graphs.)