I was also thinking that it's similar to Lavender cotton (Santolina chamaesyparissus) although its not obvious of use in chartreuse (that I know of) the plant is similar, with European origins.

http://en.wikipedia.org/wiki/S...

Christine, it's not Artemisia absinthium, they make no Chartreuse of that plant, but Absinth. I do also have the A. absinthium in my garden and it really looks and smells different.
And it's also not Santolina chamaesyparissus, leaves as well as flowers are different from my plant.
Thank you anyway for trying to help me finding this plant's name.

I think I finally found the name
Tanacetum vulgare crispum, so most of you were looking in the right direction.
In this article is explained why it is still mixed up with Artemisia and the wrong common German name 'Schwarze Edelraute' has. http://www.nymphaion.de/shop/T...
It's in German, but maybe you can use a translator.

Well what do you all think: is this the right name?

It does look correct! The Plant list gives it as a synonym of Tanacetum vulgare ..

http://www.theplantlist.org/tp...

http://www.theplantlist.org/tp...

Does this mean we are still looking for a different plant? The following sites show leaves which look different, but not so curled.

http://www.illinoiswildflowers...

http://www.paghat.com/tansy.ht...

From a German site, this translation says:

'Crispum' is a little-known variety with very beautiful, curly-leaf foliage. It is still sometimes found in old cottage gardens. I've got my plants years ago by our late neighbor. Which she had to get by the monks of the monastery of Stühlingen.Undemanding wild perennial with numerous yellow flower heads and fine zerteiltem, farnartigem leaves (hence the name!). Spread over arms quickly. The tansy is extremely versatile as jewelry and cutting perennials, a embankment fortification, and last but not least, the tansy (used as vergärte broth) provides one of the most important biological remedies for lice, mites and other pests.

http://www.pflanzen-vielfalt.d...

A map showing locations on eol .. click to enlarge, it seems to be mainly in Sweden.

http://eol.org/pages/11268009/...

For sale here ..

http://www.properplants.com/as...

Info ..

http://www.nps.gov/akso/NatRes...

[quote="JRsbugs"]It does look correct! The Plant list gives it as a synonym of Tanacetum vulgare ..

http://www.theplantlist.org/tp...

http://www.theplantlist.org/tp...

I really don't know what standards the Plant List uses to give different plants the same name. If we assume it is the T.vulgare crispy, I can only say it differs in smell and leaves from the T. vulgare and even the flowers are a bit different.

Does this mean we are still looking for a different plant? The following sites show leaves which look different, but not so curled.

It might be we are still looking for a different plant, but I'm pretty sure after reading the comment on the German website (see link in my previous post).

This is the translation of that link:

We have offered so far this plant under the name in which it has come to us: Artemisia species 'Chartreuse'. In the meantime, it has become clear that it is no wormwood but a close relative of a tansy. The correct name of Tanacetum vulgare forma crispum [DC] is with high probability. Thus the herb collectors circulating information about this plant have become very doubtful, because it was always is said this plant is the main component of the French Chartreuse liqueur. In the real Chartreuse liqueur there are used over a hundred different herbs, and tansy is too toxic to be the main ingredient in liqueur. Due to its high toxicity, tansy is also no longer used to cure worm diseases. It was probably only the fragrance of the leaves that gave the suggestion it was used for the Chartreuse liqueur and due to that given the wrong name to the plant. The fragrance is a good reason to keep this plant in the garden. Touching the leaves releases a cloud of fragrance, and they smell better and sweeter than the common tansy. The plant has attractive crinkled leaves and cuts a fine figure as perennial in the perennial border.

http://www.illinoiswildflowers...

http://www.paghat.com/tansy.ht...

As someone noticed before in this thread, the leaves look very different on my pictures, but it's the same plant. Maybe it's a natural difference.
I will have a better look when it comes up again.