Abstract

Fremstad, E. 2004. Mesterrot Peucedanum ostruthium i Midt-Norge. Blyttia 62: 82-90.
Masterwort Peucedanum ostruthium in Central Norway.

In Norway, Masterwort Peucedanum ostruthium is an alien species, believed to have been introduced in the Middle Ages as a medicinal plant. In Central Norway, it was found for the first time in 1942 in Molde, Møre og Romsdal county, and in 1944 in Melhus, Sør-Trøndelag county, and later at another seven sites in Melhus and the neighbouring Midtre Gauldal up to the early 1990s. In 2003 all the sites were revisited to evaluate population sizes and viability of the species. It was not refound at two of the sites, one of which was rather inaccurately described on the herbarium label. One new site was discovered in Soknedal, Midtre Gauldal. All populations in Sør-Trøndelag are found close to farm-houses or mountain farms («seter») in the middle boreal zone, 305-565 m a.s.l. It grows in old meadows and pastures on slightly damp and nutrient-rich soils, sometimes in disturbed sites with ruderals. It is not known when and how masterwort arrived at the present sites. At the seven sites in Sør-Trøndelag where masterwort was found in 2003 it has many small populations and several rather large ones. The majority of the populations produced seeds in 2003. Nonetheless, masterwort shows no tendency to spread outside the farms. The Molde site is situated in the south boreal zone, 15-20 m a.s.l., on the outskirts of a private garden, where it arrived as a weed. Some of the small populations can easily be eradicated by habitat destruction and changes in land use. So far, no measures are taken for the preservation of the species in Central Norway, but several landowners have been made aware of its value as a part of our cultural heritage and biodiversity.

Eli Fremstad, Norges teknisk-naturvitenskapelige universitet, Vitenskapsmuseet, Seksjon for naturhistorie, 7491 Trondheim. E-post: eli.fremstad@vm.ntnu.no

Blyttia 62 (2)
Blyttias hjemmeside
Lagt ut 03.12.2004 JW