Someone said "a rose by any other name would smell as sweet" in your case a peony. If you want a cultivar name, it might be "Lobata" or possibly "Peregrina". I would welcome a volunteer peony by any name. Al

You could also ask a member of the Danish Peony Society of what cultivars were in commerce at the time your house was built. Probably is one of the ones Al mentioned.

To my knowledge the Danish Society is active.

Here is a link that might be useful: Danish Peony Society

thanks for the help :)
as far as i could see the peony was peregrina, but thats a species and not a cultivar, am i right?
i dont think the peony is as old as the house though, being that it was build in the 1850's. :)

There is some debate as to if it is a separate specie or or a cultivar with in that family,. Not officinalis, however. Because of the slight ruffle on the edges and the single carpel vs the regular three carpels on officinalis you an rule it out. However, there were several cultivars that were marketed just after WWI to celebrate the Armistice that are similar to this. Think "in Flanders fields where poppies grow".

You might want to get Halda's The Genus Paeonia for some drawings of several species. Hong's new book has other drawings but is much more expensive.