This is the editio princeps of the first book of the Florilegium Coislinianum, an important Byzantine anthology dated to the 9th or 10th c. The critical text presented here is based upon a detailed examination of all the known witnesses of the florilegium, and it has been thoroughly compared with its sources. It is supplemented with a philological introduction which studies the manuscript tradition and the relationship of the manuscripts, explains the orthographical peculiarities of the tradition, defines the ratio edendi and discusses the most relevant textual corruptions of the archetype.