My vote goes with Andrey! Except I know it by Anemonella thalictroides. Has the name changed? https://www.google.co.uk/search?q=A...PAP&biw=1536&bih=742&sei=LXo2UZ2DOYzFPYyUgMAD
Concur with Andrey with regard to the above suggestions. Leaves not a match for Sanguinaria, Fragaria or Hepatica.
As with many names recently, they change it back and forth. It is head-spinning time in taxonomy and nomenclature. For this species, Wikipedia gives short history: http://en.wikipedia.org/wiki/Thalictrum_thalictroides
It's definitely Thalictrum thalictroides. Now I have to remember why I bought it. :) Thanks everybody! What a great forum!
Thanks Andrey. Quote wiki.... "Originally described as Anemone thalictroides by Linnaeus in 1753. It was transferred to a new, monospecific genus, Anemonella, by Édouard Spach in 1839.[2] Although similar to plants in the genus Thalictrum, Sprach considered the diminutive size, umbelliform inflorescence, and tuberous roots of this species to be distinctive enough to designate a new genus. JRB Boivin considered this distinction suspect, and transferred the species to the genus Thalictrum in 1957.[3] Molecular evidence supports the placement of the species within Thalictrum,[4] and this placement is accepted by several modern treatments.[5]" Hmm! Hardy a recent name change! 1957. Shame that even famous plants people such as Dan Hinkley show it incorrecly named as Anemonella in his wonderful book.
I think it is just a different opinion. "The Plant List" site calls it Anemonella thalictroides (L.) Spach and as a synonym Thalictrum thalictroides (L.) A.J. Eames & B. Boivin. http://www.theplantlist.org/tpl/record/tro-27100858
The molecular evidence may not be known by everyone. Then there will be those who think molecular evidence does not overrule gross morphology.