Sanguinaria is a monotypic genus - it contains just the one species, Sanguinaria canadense, The Canadian Bloodroot.
Although the wild form of this species is a lovely plant, it suffers from having too few petals and these can be quickly lost. One puff of wind on a three-day-old flower and it is a stump for another year!
The best of the double forms, "Multiplex", has a large well-filled pom-pom with enough petals to spare a few and still look good, from bud to demise. It is every bit as easy to grow as the type straight species, given a leafy, peaty soil in half or part shade, or even full sun if an adequate supply of water at the roots, in summer, can be guaranteed.
The display that a clump of this can make, in a humus rich spot such as a peat garden, in early spring, is not to be missed.
Order from Autumn and Spring lists.