Caulophyllum thalictroides, the blue cohosh, a species of Caulophyllum, is a flowering plant in the Berberidaceae family. It is a medium-tall perennial with blue berry-like fruits and green foliage. It is native to North American partial-shade woodlands. It is a "women's herb" and the roots are the valuable part.
I sell it as a tincture here.