De Viribus Herbarum (On the properties of plants), also known by the author's pseudonym, Macer Floridus, is a Latin hexameter poem on the properties of herbs. It was written, probably by Odo of Meung-sur-Loire, in the 11th century. It was still in scholarly use as late as the 16th century, but was superseded by more comprehensive herbals. Source: Wikipedia (en)