Ibn al-Baytar systematically recorded the additions to pharmacy made by medieval Islamic physicians, who added between 300 and 400 types of medicines to the roughly one thousand known since antiquity.

"Ibn al-Baitar’s largest and most widely read book is his Compendium on Simple Medicaments and Foods. It is a pharmacopoeia (pharmaceutical encyclopedia) listing 1400 plants, foods, and drugs and their uses. It is organized alphabetically by the name of the useful plant or plant component or other substance—a small minority of the items covered are not botanicals. For each item, Ibn al-Baitar makes one or two brief remarks himself and gives brief extracts from a handful of different earlier authors about the item. The bulk of the information is compiled from the earlier authors. The book contains references to 150 previous Arabic authors, as well as 20 previous Greek authors.^[6][7] One of the sources he quotes the most frequently is the Materia Medica of Dioscorides, and another is Book Two of the Canon of Medicine of Ibn Sina. Both of those sources have similarities in layout and subject matter with Ibn al-Baitar's own book, but Ibn al-Baitar's treatments are richer in detail, and a large minority of Ibn al-Baitar's useful plants or plant substances are not covered at all by Dioscorides or Ibn Sina. In modern printed edition, the book is more than 900 pages long. As well as in Arabic, it was published in full in translation in German and French in the 19th century" (Wikipedia article on Ibnal-Batar, accessed 01-2017). Digital facsimile from docs.google.com at this link.