Imperatoria ostruthium L. (syn.: Peucedanum ostruthium (L.) Koch) (mountains of S and C-Eur.) – A very rare, locally naturalized escape from cultivation. Introduced for medicinal purposes in Hautes Ardennes in the 16th century and still present in the vicinity of ca. 20 villages (Saintenoy-Simon 1997). Well-documented for instance from Sourbrodt-Robertville (collections between 1957 and 1990). Furthermore known from Bihain, Boussire, Hockay, Jonkeu, Malmédy, Offagne, Ovifat, Saint-Hubert, Spa, Stavelot, Tailles and Vielsalm (although probably disappeared from some of these locations). Imperatoria ostruthium is usually found naturalized in damp meadows, hedges, wood margins, shady ditches and off-ramps or damp road verges. Most populations are located in the highest parts of Belgium (500-600 m a.s.l.).
Selected literature:
Dewalque G. (1902-1903) L’Imperatoria ostruthium L. en Belgique. Bull. Soc. Roy. Bot. Belg. 41(3): 171-175.
Fremstad E. (2004) Mesterrot Peucedanum ostruthium i Midt-Norge. Blyttia 62: 82-90.
Kopecký K. (1973) Die Beziehung zwischen Siedlungsgeschichte und Verbreitung von Imperatoria ostruthium im Gebirge Orlické hory (Adlergebirge, Nordostböhmen). Folia Geobot. Phytotax. 8(3): 241-248.
Nilsson E. (1982) Masterroten: hemkar men myckfull. Svensk Bot. Tidskr. 76(2): 83-89
Saintenoy-Simon J. (1997) Excursion dans la région de Waimes et de Bütgenbach, le 14 septembre 1996. Adoxa 17: 19-21.
Svedjemyr O. (1989) Mästerroten, Peucedanum ostruthium – läkeväxt från medeltid. Svensk Bot. Tidskr. 83: 149-155.