In article , Evert
Meulie esq. writes
Do you mean these: http://graysharbor.wsu.edu/Weeds/tansy.gif ?

I can see some similarity, I don't think they're the same... The tansy
seems to have its buds closer together than the kind on the
painting...

Assuming that the painting is accurate, it's not tansy. For a start the
foliage is different.

The gross form of the inflorescence looks similar to that of Buddleia x
weyeriana, but the jizz is wrong for this.

The gross form of the inflorescence again looks similar to that of
Acacia, but the foliage is wrong for this.

I interpret the plant to have capitate clusters of flowers borne at
intervals along leafless flowering branches. I am assuming that the
foliage belongs to the same plant.
--
Stewart Robert Hinsley