Aruncus species ?- Warsaw

Plant for ID-PC-04-08.09.2015 : 4 posts by 2 authors. Attachments (3)
please identify the plant in the picture. It is from the Lazienky Palace Garden, Warsaw. Help me.
This is probably a species of Aruncus but there is a smaller chance it could be AstilbeAruncus are white/cream flowered and the inflorescence is generally more open, with more horizontal branches than Astilbe.