Basic Facts Odo Magdunensis and the Macer floridus Tobias Niedenthal (Forschergruppe Klostermedizin, Würzburg) — ORCID: 0000-0001-5975-1210 Abstract Odo Magdunensis’ De viribus herbarum (transmitted as the Macer floridus) is a Latin hexameter didactic poem on medicinal plants that became a standard point of reference for medieval materia medica. The work condenses late antique authorities, especially Dioscorides, Pliny and Galen, and in expanded form incorporates graded pharmacology lifted from Constantinus Africanus ( Liber graduum). Its transmission is marked by openness to rearrangement and accretion, including the Spuria Macri and the emergence of the German prose Macer (c. 1220), which reflects shifting audiences and functions. Persistent problems include the instability of author attributions under the name “Macer” and recurrent uncertainties of drug identification, while the reception can be traced into early modern herbals and, in selected cases, into later phytotherapeutic discourse. This brief outlines authorship, dating, transmission, translations, and current research trends, linking the philological work of Johannes G. Mayer and Konrad Goehl (2013) [MG], Bernhard Schnell and William Crossgrove (2003) [SC], and Ulrike Jansen (2013) [J] with the current significance of the plants discussed. Keywords: Odo of Meung; Odo Magdunensis; Macer floridus; De viribus herbarum; German Macer; medieval herbal; didactic poetry; Salerno; Constantinus Africanus; Liber graduum; vernacular translations; textual transmission; Spuria Macri; reception history Author and author-construct The author of De viribus herbarum is identified with Odo Magdunensis (Odo of Meung), but biographical indications remain sparse. On the basis of linguistic profile and education, he was more likely a magister than a practising physician [SC 27]. In transmission, the text circulates under the author name “Macer”. Explicit ascriptions such as “Odonis magdunensis opusculum de naturis herbarum” (Dresden, Dc 160, late 12th century) or “auctore Odone dicto macro florigio” (Douai 217, 13th century) are rare. The identification with the ancient Aemilius Macer (d. 16 BC) is less a reliable author attribution than a signal of auctoritas. The false attribution to Aemilius Macer is explained by medieval canon formation, in which ancient names served as guarantors of credibility. Ovid (Trist. IV, 10, 43-44) and Isidore (Etym. XII, 7, 9) mention a Macer as author of works on birds, snakes, and herbs. The byname “floridus” is first attested in the 13th century (Douai 217) and was canonised through incunable printing. It may have arisen through misreading from “philosophus” [MG]. The competition with attributions such as “Odo Muremundensis” (Morimond) requires stemmatic clarification [SC 27, 29]. Dating The earliest mention of the Macer occurs around 1100 in Sigebert of Gembloux (De scriptoribus ecclesiasticis). Accordingly, the final redaction (77 chapters) is dated before 1112. For the shorter original version (ca. 50–60 chapters) a window within the eleventh century is assumed; the older attribution to the ancient Aemilius Macer has been rejected as irrelevant [Crossgrove 1994; Flood 1976; SC 24–26]. Tobias Niedenhal: Walahfrid Strabo und der Hortulus Version 1.1; 2 Jan 2026. DOI: 10.5281/zenodo.17410453 1