Mattheus Platearius (active during the 12th century) was a physician from the medical school of Salerno, near Naples in Italy. Little is known about him, but he is thought to have produced a Latin treatise on pharmaceutical plants and herbs entitled Circa instans. The text was extremely popular during the medieval period, surviving in about 240 manuscripts, and it was translated into many vernacular languages (including English, French, German, Hebrew, and Dutch).

This French version of the Circa instans appears in a manuscript alongside Roger Frugardi’s Chirurgia (Surgery), made in Amiens during the first quarter of the 14th century. The beginning of Platearius’ text is marked by a table of contents and a full-page illustration of an apothecary shop, followed by four pages of illustrations detailing medical consultations and surgical treatments.